Adding migrations to clean Rococo Gov 1 storage & reserved funds (#1849)

Following
[polkadot#7314](paritytech/polkadot#7314) and
after merging #1177 this
PR solves #1618

The following is a summary of the outcome of the migration.

| Module | Total Accounts | Total stake to unlock | Total deposit to
unreserve |
| ------- | --------------- | --------------------- |
-------------------------- |
| Elections Phragmen | 27 | 1,132.821063320441 ROC | 1.465386531600 ROC
|
| Democracy | 69 | 2733.923509345613 ROC | 0.166666665000 ROC |
| Tips | 4 | N/A | 0.015099999849 ROC |

The migrations will also remove the following amount of keys

103 Democracy keys 🧹
5 Council keys 🧹
1 TechnicalCommittee keys 🧹
25 PhragmenElection keys 🧹
1 TechnicalMembership keys 🧹
9 Tips keys 🧹

polkadot/runtime/rococo/src/lib.rs

@@ -1414,6 +1414,52 @@ pub type Migrations = migrations::Unreleased;
 pub mod migrations {
 	use super::*;
 
+	use frame_support::traits::LockIdentifier;
+	use frame_system::pallet_prelude::BlockNumberFor;
+
+	parameter_types! {
+		pub const DemocracyPalletName: &'static str = "Democracy";
+		pub const CouncilPalletName: &'static str = "Council";
+		pub const TechnicalCommitteePalletName: &'static str = "TechnicalCommittee";
+		pub const PhragmenElectionPalletName: &'static str = "PhragmenElection";
+		pub const TechnicalMembershipPalletName: &'static str = "TechnicalMembership";
+		pub const TipsPalletName: &'static str = "Tips";
+		pub const PhragmenElectionPalletId: LockIdentifier = *b"phrelect";
+	}
+
+	// Special Config for Gov V1 pallets, allowing us to run migrations for them without
+	// implementing their configs on [`Runtime`].
+	pub struct UnlockConfig;
+	impl pallet_democracy::migrations::unlock_and_unreserve_all_funds::UnlockConfig for UnlockConfig {
+		type Currency = Balances;
+		type MaxVotes = ConstU32<100>;
+		type MaxDeposits = ConstU32<100>;
+		type AccountId = AccountId;
+		type BlockNumber = BlockNumberFor<Runtime>;
+		type DbWeight = <Runtime as frame_system::Config>::DbWeight;
+		type PalletName = DemocracyPalletName;
+	}
+	impl pallet_elections_phragmen::migrations::unlock_and_unreserve_all_funds::UnlockConfig
+		for UnlockConfig
+	{
+		type Currency = Balances;
+		type MaxVotesPerVoter = ConstU32<16>;
+		type PalletId = PhragmenElectionPalletId;
+		type AccountId = AccountId;
+		type DbWeight = <Runtime as frame_system::Config>::DbWeight;
+		type PalletName = PhragmenElectionPalletName;
+	}
+	impl pallet_tips::migrations::unreserve_deposits::UnlockConfig<()> for UnlockConfig {
+		type Currency = Balances;
+		type Hash = Hash;
+		type DataDepositPerByte = DataDepositPerByte;
+		type TipReportDepositBase = TipReportDepositBase;
+		type AccountId = AccountId;
+		type BlockNumber = BlockNumberFor<Runtime>;
+		type DbWeight = <Runtime as frame_system::Config>::DbWeight;
+		type PalletName = TipsPalletName;
+	}
+
 	/// Unreleased migrations. Add new ones here:
 	pub type Unreleased = (
 		pallet_society::migrations::VersionCheckedMigrateToV2<Runtime, (), ()>,
@@ -1426,6 +1472,21 @@ pub mod migrations {
 		paras_registrar::migration::VersionCheckedMigrateToV1<Runtime, ()>,
 		pallet_referenda::migration::v1::MigrateV0ToV1<Runtime, ()>,
 		pallet_referenda::migration::v1::MigrateV0ToV1<Runtime, pallet_referenda::Instance2>,
+
+		// Unlock & unreserve Gov1 funds
+
+		pallet_elections_phragmen::migrations::unlock_and_unreserve_all_funds::UnlockAndUnreserveAllFunds<UnlockConfig>,
+		pallet_democracy::migrations::unlock_and_unreserve_all_funds::UnlockAndUnreserveAllFunds<UnlockConfig>,
+		pallet_tips::migrations::unreserve_deposits::UnreserveDeposits<UnlockConfig, ()>,
+
+		// Delete all Gov v1 pallet storage key/values.
+
+		frame_support::migrations::RemovePallet<DemocracyPalletName, <Runtime as frame_system::Config>::DbWeight>,
+		frame_support::migrations::RemovePallet<CouncilPalletName, <Runtime as frame_system::Config>::DbWeight>,
+		frame_support::migrations::RemovePallet<TechnicalCommitteePalletName, <Runtime as frame_system::Config>::DbWeight>,
+		frame_support::migrations::RemovePallet<PhragmenElectionPalletName, <Runtime as frame_system::Config>::DbWeight>,
+		frame_support::migrations::RemovePallet<TechnicalMembershipPalletName, <Runtime as frame_system::Config>::DbWeight>,
+		frame_support::migrations::RemovePallet<TipsPalletName, <Runtime as frame_system::Config>::DbWeight>,
 	);
 }