refactor!: rm GetSignBytes

[kocubinski]

Description

Since the legacy amino JSON codec is now deprecated (#16110) and no longer used in production code paths (#16024) we can now remove a lot of unused code, code smells (global vars), and cyclic module dependencies.

The following cyclic dependencies are removed compared to main

/x/auth/ <-> /x/authz/
/x/auth/ <-> /x/group/
/x/authz/ <-> /x/group/
/x/authz/ <-> /x/gov/
/x/bank/ <-> /x/group/

cosmos/cosmos-sdk

• Remove global legacy amino JSON codecs from modules.
• Remove GetSignBytes implementations from messages which were using them.
• The simulation.GetOrGenerate no longer requires a codec, and is now 4-arity instead of 5.

x/auth

• Add global RegressionTestingAminoCodec to x/auth/legacytx package to replace the global codecs for use in regression tests. This should be deleted eventually.

cosmossdk.io/api

• Add missing annotations on gov messages with Coins fields ensuring legacy consistency.

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[tac0turtle]

utACK. the encoding tests are passing but later on during QA ill pull out a ledger to test things with

[kocubinski]

This advanced #13025