[Epic]: auth/tx migration

[tac0turtle]

Summary

In Q3 the sdk team rewrote tx decoding into x/tx. It is used in many places throughout the code base, but there is still usage of auth/tx used throughout the codebase.

Problem Definition

Deprecate auth/tx in favor of using x/tx everywhere

Work Breakdown

• identify usage of auth/tx throughout the codebase
• Remove usage of auth/tx, add new features to x/tx in order to achieve this.
• mark auth/tx as deprecated.

Other issues to be resolved with this work

• Migrate CLI commands in x/auth/tx to comet txserver #15888
• [Documentation]: Add readme to x/tx #17828
• [Feature]: x/Auth and x/tx module common types unification/conversion #17530