tests(erc20): Add ERC20 integration test setup

[MalteHerrmann]

Description

Supersedes #2044.

This PR adds the basic setup for adding the ERC20 EVM extension integration tests.
Specifically, it does the following:

• Add basic Ginkgo grid for adding integration tests
• Utilities to the integration network:
  • gov methods to submit a proposal and query params
  • erc20 utils to register a token pair using the full governance flow in the integration setup
  • some queries
  • a util to fund an account with tokens of a specific denomination (this might be refactored after conv. with @facs95)
• Add necessary contracts for testing different cases:
  • a contract to call the EVM extension
  • an OpenZeppelin v5 ERC20 contract
  • a contract to call ERC20 contracts without the extra allowance and metadata methods
• also it splits the integration test setup from the Unit testing suite for clear separation of concerns

[fedekunze]

LGTM pending constant for the expected event

[MalteHerrmann]

done! The linter is only complaining about some functions that will be used in tests, so that failing is as expected.