Update cosmos/cosmos-sdk to v0.46

[RiccardoM]

Cosmos v0.46.0 has been released, and it contains a lot of changes. Before upgrading to it we need to make sure the following dependencies are ready (I will use the list to track any PR/issue related to the corresponding upgrades, if any):

• [x] cosmos/ibc-go Compatible version: v5.0.0-rc1
• [ ] CosmWasm/wasmd
  • https://github.com/CosmWasm/wasmd/pull/938