typing: add a handful more annotations to `mercurial/vfs.py`...
typing: add a handful more annotations to `mercurial/vfs.py`
These came out of refactoring into a protocol class, but they can stand on their
own.
The `audit` callback is kinda screwy because the internal lambda and the callable
for `pathutil.pathauditor` have different args and a different return type. It's
conditionalized where it is called, and can be cleaned up later if desired.