"Go version autonomy" for important packages used by the keeper, like go/types and go/format

[thehowl]

See this PR review comment

With the go/types typechecker and go/format being used inside the VM keeper to check and format Go code, we have a high dependency of our consensus on the Go versions being used by the validators.

Eventually, we should look to have a Go-version-independent fork of both of these. The go type checker can probably eventually be removed if the Gno type checking reaches the same quality as the Go compiler/typechecker.

cc/ @moul