typing: add some trivial type hints to `mercurial/match.py`
These were new methods since hg
3dbc7b1ecaba, but surprisingly pytype couldn't
figure them out.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}