fix(str): Add some changes from the internal STRv2 audit

[MalteHerrmann]

Description

This PR adjusts some things found in the internal STR v2 audit:

• The handling of the maxUint256 approvals for the ERC-20 transfers was not correctly implemented. The bank module's SendAuthorization does not have the same notion of an unlimited approval (check here) as e.g. the StakeAuthorization does (see here and here). Hence, the handling for this ERC-20 characteristic has to happen on the level of the EVM extension.
• Passing the empty address (common.Address{}) did not return errors before, even though it is the case for the transfer, transferFrom and approve methods on a standard ERC-20 Solidity contract by OpenZeppelin.
• During the OnRecvPacket in the ERC-20 IBC middleware, we were wrongfully checking if the sender address was a module address, when rather it should be checked for the receiver.
• Fix some test logic for the IBC callbacks.
• Use IsPositive() rather than IsZero() || IsNegative().

[GAtom22]

LGTM!! Great work @MalteHerrmann!!

[Vvaradinov]

LGTM!

[MalteHerrmann]

The failing tests are the same failling ones as on the base branch after merging #2476, which is okay as those are going to be removed in a follow-up PR. 👍