Audit UUID functions for correctness

It was discovered in #11457 and dolthub/go-mysql-server#3695 that `BIN_TO_UUID` behavior in Dolt does not match that of MySQL.

We need to audit `BIN_TO_UUID` for other input types (such as strings that convert to numbers) as well as other UUID functions, such as `UUID_TO_BIN`, for correctness.

Locate the BIN_TO_UUID and UUID_TO_BIN implementations and any existing tests. Compare their behavior with MySQL for the input types described in the issue, including strings that convert to numbers, and consider the audit done when the UUID functions match the reference behavior.

Written by the indexing model from the issue text.