Audit x/gov v0.47...v0.50

[likhita-809]

[likhita-809]

Changes found and tested when necessary:

• we have constitution field in genesis state which defines purpose of chain
• Expedited option is provided in gov v1 proposal and it works fine.
• previously proposal status used to log only when proposal exec passes, now it logs even when proposal passes but fails to execute.
• we are using MsgRouter interface in NewKeeper
• we are checking that proposal metadata's title and summary matches the proposal's title and summary
• migration to KVStoreService
• gRPC query methods are now handled by queryServer instead of Keeper
• Usage of collections and removal of several methods
• submit-legacy-proposal and cancel-software-upgrade cmds no longer live in gov module
• small json format fix for gov vote tx response

Changes needed:

• few nits
• removal of GetSigners
• improve codecov & add missing tests