Clean up deprecated cosmos-sdk 0.46 API usage

[JimLarson]

What is the Problem Being Solved?

Cosmos-sdk has marked a number of the APIs we're using as "deprecated". See the 0.46 upgrade notes. While we're not forced to change the API usage until we do a cosmos-sdk upgrade to a version where the legacy compatibility is actually removed, doing so will exacerbate an already difficult migration process. We can break up the migration effort by cleaning up deprecated interfaces early.

Description of the Design

We want to make the following changes:

• change sdk.Int and sdk.Uint to use their new location in the math package;
• use x/errors instead of types/errors;
• module-native parameter get/set instead of x/params. See the mint module's migration for example.
• the x/gov module has a new v1 API;
• our custom Coins min and max methods can be dropped in favor of the built-in version.

Security Considerations

N/A - these changes typically replace use of forwarding placeholders or identical implementations.

Scaling Considerations

N/A

Test Plan

N/A

Upgrade Considerations

N/A