Fix 'TODO: support wildcard matching in comparator names (RFC 4790)' issue in sifter\comparator.py

[CodeFactor](https://www.codefactor.io/repository/github/python-sifter/sifter3) found an issue: TODO: support wildcard matching in comparator names (RFC 4790)

It's currently on:
[sifter\comparator.py:36
](https://www.codefactor.io/repository/github/python-sifter/sifter3/source/master/sifter/comparator.py#L36)Commit 6e6601ee7d45643e613c73a1db22a6d81d4b5942