chore: Add v0.46.0 RC1 release notes and changelog (#12015)

* Add release notes

* wip

* Add release notes

* Add changelog rc1

* Add x/gov msg executor == gov modul acct

CHANGELOG.md

@@ -37,6 +37,8 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ## [Unreleased]
 
+## [v0.46.0-rc1](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.46.0-rc1) - 2022-05-23
+
 ### Features
 
 * (types) [#11985](https://github.com/cosmos/cosmos-sdk/pull/11985) Add a `Priority` field on `sdk.Context`, which represents the CheckTx priority field. It is only used during CheckTx.

RELEASE_NOTES.md

@@ -0,0 +1,71 @@
+# Cosmos SDK v0.46.0 Release Notes
+
+This release introduces several new important updates to the Cosmos SDK. The release notes below provide an overview of the larger high-level changes introduced in the v0.46 release series.
+
+That being said, this release does contain many more minor and module-level changes besides those mentioned below. For a comprehsive list of all breaking changes and improvements since the v0.45 release series, please see the [CHANGELOG](https://github.com/cosmos/cosmos-sdk/blob/release/v0.46.x/CHANGELOG.md).
+
+## New Module: `x/group`
+
+The previous v0.43 series focused on simplifying [keys and fee management](https://github.com/cosmos/cosmos-sdk/issues/7074) for SDK users, by adding `x/feegrant` and `x/authz`. v0.46 finishes this work by introducing `x/group`.
+
+`x/group` provides functionality to define on-chain groups of people that can execute arbitrary messages based on agreed upon rules. A simple use-case of `x/group` is to create on-chain multisigs (with updateable members and thresholds), but `x/group` can also be used to create more complex DAOs.
+
+The `x/group` module revolves around 3 concepts:
+
+- A **group** is simply an aggregation of accounts with associated weights.
+- A **group policy** is a group with a set of rules attached, called decision policy. The decision policy defines how voting and arbitrary message execution happens (e.g. does a proposal pass on 50% yes? 2/3 yes? is there a way to veto? etc). Each group policy has its own an on-chain account, so can hold funds. Managing group membership separately from decision policies results in the least overhead and keeps membership consistent across different policies.
+- Any member of a group can submit a **proposal** for a group policy account to decide upon. A proposal consists of a set of messages that will be executed if the proposal passes voting.
+
+If a proposal passes the decision policy's rules after its voting period, then any account can send a `MsgExec` against this proposal to execute the `sdk.Msg`s included in the proposal.
+
+For more details about `x/group`, please refer to [the SDK documentation](https://docs.cosmos.network/master/modules/group/) and [ADR-042](https://github.com/cosmos/cosmos-sdk/blob/main/docs/architecture/adr-042-group-module.md).
+
+The folder structure of `x/group` contains an `internal` folder, which holds a custom ORM used only by `x/group` (and which will be replaced by the [new ORM](https://github.com/cosmos/cosmos-sdk/blob/main/docs/architecture/adr-055-orm.md)) as well as a new implementation of `Dec` (for decimals) based on [`cockroachdb/apd`](https://github.com/cockroachdb/apd), which serves as a proof-of-concept for the [new `sdk.Dec`](https://github.com/cosmos/cosmos-sdk/issues/11783).
+
+## `Msg`-based Gov Proposals
+
+In an effort to [align](https://github.com/cosmos/cosmos-sdk/issues/9438) `x/gov` with `x/group`, the SDK v0.46 release introduces a new Protobuf package: `cosmos.gov.v1`.
+
+The biggest change compared to the previous `cosmoss.gov.v1beta1` is in `MsgSubmitProposal`: instead of defining gov router proposal handlers, the v0.46 gov execution models is based on `sdk.Msg`s:
+
+```diff
+message MsgSubmitProposal {
+-  google.protobuf.Any content                       = 1 [(cosmos_proto.accepts_interface) = "Content"];
++  repeated google.protobuf.Any messages             = 1 [(cosmos_proto.accepts_interface) = "sdk.Msg"];
+  repeated cosmos.base.v1beta1.Coin initial_deposit = 2 [(gogoproto.nullable) = false];
+  string                            proposer        = 3 [(cosmos_proto.scalar) = "cosmos.AddressString"];
++  // metadata is any arbitrary metadata attached to the proposal.
++  string metadata = 4;
+}
+```
+
+For example, instead of broadcasting a `v1beta1.MsgSubmitProposal` with content a `SoftwareUpgradeProposal`, the proposer would submit a `v1.MsgSubmitProposal` with a `/cosmos.upgrade.v1beta1.MsgSoftwareUpgrade` message. When the proposal passes, the `sdk.Msg` will be executed by the `Msg` service router (instead of going through the gov proposal handlers).
+
+The `sdk.Msg`s in the proposal are executed on behalf of the `gov` module account. This means that each of the `sdk.Msg` inside the proposal must have their `GetSigners()` method return exactly one address, which is the `gov` module account's address.
+
+A `metadata` field has also been added to `MsgSubmitProposal` and `MsgVote`, for users to provide optional justification for their action.
+
+From a client perspective, the new gov v1 is purely additive. All `v1beta1` Protobuf defintions, queries and `Msg`s still work. Morever, users can also submit `v1beta1` legacy proposals using the `v1` `Msg` service, by including a `MsgExecLegacyContent` inside the `v1.MsgSubmitProposal`. It is recommended to switch to gov `v1` during v0.46, as the gov `v1beta1` backwards-compatibility might be removed in a future version.
+
+As an app developer, some API changes from `v1beta1` to `v1` are to be expected in the `x/gov` Keeper, and are documented in the [`UPGRADING.md` guide](TODO).
+
+## Baseapp PostHandlers
+
+A transaction's lifecycle in the SDK goes through BaseApp's `CheckTx` and `DeliverTx`, and both of them run the AnteHandlers; then, `DeliverTx` also runs the `sdk.Msg`s execution (in BaseApp's `runMsgs` function).
+
+In v0.46, we added "PostHandlers" to the SDK. PostHandlers are like AnteHandlers (they have the same signature), but they are run _after_ `runMsgs`. One use case for PostHandlers is transaction tips (see below), but other use cases like unused gas refund can also be enabled by PostHandlers.
+
+Please note that the PostHandlers run **in the same store branch** as `runMsgs`. This means that if the PostHandlers fail, then all the state from `runMsgs` will also be reverted. As a reminder, the AnteHandlers run in a separate store branch before `runMsgs`. This means that the v0.46 SDK currently creates 2 store branches when running transactions:
+
+- one for AnteHandlers,
+- one for `runMsgs` and PostHandlers.
+
+## Transaction Tips and `SIGN_MODE_DIRECT_AUX`
+
+Transaction tips are a mechanism to pay for transaction fees using another denom than the native fee denom of the chain.
+
+The transaction initiator signs a partial transaction (called [`AuxSignerData`](https://github.com/cosmos/cosmos-sdk/blob/v0.46.0-beta2/proto/cosmos/tx/v1beta1/tx.proto#L230-L249)) without specifying fees, but uses a new `Tip` field. They send this `AuxSignerData` to a fee relayer who will choose the transaction fees and broadcast the final transaction, and the SDK provides a mechanism that will transfer the pre-defined `Tip` to the fee payer, to cover for fees. A market between tippers and feepayers could arise, based on exchange rates between the tip denom and the fee denom.
+
+For this mechanism to work, the SDK introduces a new sign mode, `SIGN_MODE_DIRECT_AUX`, whereby the signer signs over the transaction body and their own signer info, but not over fees or other signers' info. This sign mode is not limited to transaction tips though, and can be used in any multi-signer transaction, where N-1 signers sign using `SIGN_MODE_DIRECT_AUX`, and only one signer, the fee payer, signs using `SIGN_MODE_DIRECT`, allowing for a better UX for the N-1 other signers.
+
+The transaction tips decorator is NOT enabled by default on the SDK. If you want to include transaction tips on your chain, please enable `setPosthandler` in your `app.go` and include the tips decorator inside: see [simapp/app.go](https://github.com/cosmos/cosmos-sdk/blob/d416ee86b6a000e564b88affb8d1c82b3ce72034/simapp/app.go#L447-L467) for a template.