* Clean code
- using type().interfaceId to improve readeability of ERC165 registration
- hardcoding some keccak256 that are otherwise computed at construction.
* hardcode keccak256 result
* Improve code readeability using try/catch
* Remove hardcoded hash
tests show that solc 0.8.0 does the optimization as expected
* Use try/catch to improve readability
* ERC165Checker: Do not revert when returndata is empty + new test
* Address PR comments
* improve testing of ERC721Receiver errors
* put back comment about invalid interface id
* coverage does not support 0.8.1. Reverting back to 0.8.0
* bubble all data with length > 0 if onERC721Receive fails.
* Fix test: revert without message trigger is bubble with the default message
* using enum object to improve readability
