feat: remove x/authz dependency from precompiles

[cloudgray]

Description

Removal of x/authz dependency on precompiles

• Remove authzKeeper dependency from common Precompile struct
• For staking and ics20 precompile
  • remove authorization methods (Approve, Revoke, IncreaseAllowance, DecreaseAllowance, Allowance) and its usage.
• For erc20 precompile
  • Add Allowance state CRUD methods in x/erc20 module
  • Use added Allowance state of x/erc20 module instead of Grant state of x/authz module for authorization methods (Approve, Revoke, IncreaseAllowance, DecreaseAllowance, Allowance)

Closes: #47

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[zsystm]

Looks good to me so far — the authz removal seems to be handled well.

I had one question while reviewing the test code, which I left as a comment.

Also, this is not directly related to the scope of your PR, but I noticed that some of the existing test cases don’t validate balance changes. For example, after a delete, there’s no assertion checking whether the delegator’s balance was reduced accordingly. Since the precompiled contract involves complex state transitions, I think it would be valuable to add more thorough state validation to ensure the transitions happen as expected.

This can probably be addressed in a separate PR, so just leaving this here for reference. I opened an issue to track it.

[dongsam]

I haven’t gone through everything yet, but from what I’ve seen so far in app.go and the ics20 precompile section, it looks good

I’ll continue the review when I have more time.

[cloudgray]

In the cosmos-evm context, naming convention is interfaces.go, not expected_keepers.go. It's not critical, but I think it would be better to change it for consistency

applied in dc225a2

[vladjdk]

Lgtm, thanks for the work :)