chore: sdk47 post upgrade cleanup

[tbruyelle]

Description

At AIB we worked a little bit on the sdk47/ibc-v7 migration for this repository, but then you preferred to do it on your own. Anyway, since you just merged it #918, I took the time to compare our changes and yours and I found a small list of things that could be cleaned/improved/fixed :

• de0fc66 remove remaining legacy LCD/REST queriers
• c8f4713 simulation migration : ProposalContents can be deleted if the module has no proposal messages or proposal content to be tested by simulation.
• f4b5ebb replace deprecated govv1.ParamKeyTable() by gov.ProvideKeyTable()
• befa47d fix duplicate record of ante.DeductFeeDecorator. Probably the most important one, I don't think it's OK to call this ante two times for each block.

Let's discuss if you prefer to have this in separate PRs or if some of them are not correct/well-suited.

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Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• Included the correct type prefix in the PR title
• Added ! to the type prefix if API or client breaking change
• Targeted the correct branch (see PR Targeting)
• Provided a link to the relevant issue or specification
• Followed the guidelines for building SDK modules
• Included the necessary unit and integration tests
• Added a changelog entry to CHANGELOG.md
• Included comments for documenting Go code
• Updated the relevant documentation or specification
• Reviewed "Files changed" and left comments if necessary
• Confirmed all CI checks have passed

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage

[MSalopek]

Thank you for taking the time and your contribution!

Approval.

[shaspitz]

Thanks!