[x/gamm][stableswap]: Increase max post-scaled amount to 10^34

[AlpinYukseloglu]

Background

Now that we have fully switched to geometric error tolerance, we can accommodate significantly larger asset amounts and can increase our max post-scaled amount instead of dealing with additional complexity arising from a large scaling factor multiplier.

Suggested Design

• Increase max post-scaled amount to 10^34

Acceptance Criteria

• All new and existing tests pass