chore: replace amino cosmos_dec_bytes annoation by scalar cosmos.Dec and add missing annotations (backport #17000)

[mergify]

This is an automatic backport of pull request #17000 done by Mergify.
Cherry-pick of 7ed04f7 has failed:

On branch mergify/bp/release/v0.50.x/pr-17000
Your branch is up to date with 'origin/release/v0.50.x'.

You are currently cherry-picking commit 7ed04f71b.
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Changes to be committed:
	modified:   api/cosmos/gov/v1beta1/gov.pulsar.go
	modified:   api/cosmos/mint/v1beta1/query.pulsar.go
	modified:   api/cosmos/slashing/v1beta1/slashing.pulsar.go
	modified:   api/cosmos/staking/v1beta1/genesis.pulsar.go
	modified:   proto/cosmos/gov/v1beta1/gov.proto
	modified:   proto/cosmos/mint/v1beta1/query.proto
	modified:   proto/cosmos/slashing/v1beta1/slashing.proto
	modified:   proto/cosmos/staking/v1beta1/genesis.proto
	modified:   tests/go.mod
	modified:   tests/integration/rapidgen/rapidgen.go
	modified:   x/gov/types/v1beta1/gov.pb.go
	modified:   x/mint/types/query.pb.go
	modified:   x/slashing/types/slashing.pb.go
	modified:   x/staking/types/genesis.pb.go
	modified:   x/tx/signing/aminojson/json_marshal.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   tests/go.sum

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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[julienrbrt]

I'll update the newly tagged api (https://github.com/cosmos/cosmos-sdk/releases/tag/api%2Fv0.6.1) directly in this PR.