refactor(x/gamm): move errors in balancer pool to `x/gamm/types/errors.go`

[p0mvn]

Background

Many recently added errors were defined in the balancer package. Instead, we might want to have them in types/errors.go for consistency.

Suggested Design

Move: https://github.com/osmosis-labs/osmosis/blob/3be2640a842394e962e323e9ad1885019e4e4229/x/gamm/pool-models/balancer/pool.go#L20-L27

to types/errors.go

Also, remove //nolint:deadcode and delete the unused errors

Acceptance Criteria

• balancer pool errors are moved to x/gamm/types/errors.go
• balancer pool and tests are refactored to use errors from types
• //nolint:deadcode is removed together with unused errors
• potentially duplicate errors are consolidated

[stackman27]

I can do this

[p0mvn]

Thanks for taking all these