Migrate sdk.Int to math go module

[aaronc]

One of the major goals of the Framework WG is to breakdown the monolithic SDK into smaller easier to maintain component modules. sdk.Int is used in lots of generated code and can be standalone.

The proposed path for modularizing math functionality is:

• create a new math go module in this repo with a copy of the current Int functionality
• replace the existing sdk.Int with aliases to the math go module as was done for the migration of types/errors to the standalone errors go module

[aaronc]

Related to #11783

[alexanderbez]

Thanks for creating this. Will tackle this shortly.

[aaronc]

Thanks for creating this. Will tackle this shortly.

Awesome thank you 🙏