Test functions that take VARBINARY against VARCHAR with character sets.

Not just tests, because in the process of determining what needed to be tested, I discovered that CRC32 was defined to take a VARCHAR, which it then converted to bytes itself, rather than a VARBINARY, which would have done it via CAST. Even though there were YAML tests for CRC32 with BIT input.

Note also that the new expected results were taken from MySQL 5.6.6, since for once there didn't seem to be anything to object to in its behavior.