support for expectRevert(bytes4)

[ovatman]

Resolves #466

This PR contains

• matching expectRevert(bytes4) selector in cheatcode support
• After revert happens, when checking to clear the revert previous version was checking the whole output with the expected reason except the initial 4 bytes. This version just checks the last 32 bytes which contain the whole selector information (regardless of the type of parameter)

[anvacaru]

There are at least two tests that are skipped because we didn't have support for this cheatcode. Can you remove them from the *-skip and *-skip-legacy lists?

• testFail_expectRevert_bytes4
• test_expectRevert_bytes4

[ovatman]

There are at least two tests that are skipped because we didn't have support for this cheatcode. Can you remove them from the *-skip and *-skip-legacy lists?

* `testFail_expectRevert_bytes4`

* `test_expectRevert_bytes4`

They have been added now.

[ovatman]

When bytes4 type parameter is used some of the information is not directly included in the EXPECTED data since they become constant values, such as the size of the expected output. Here we set them manually to constant values.

[anvacaru]

Approved with some formatting comments.