lfs: fix various signature mismatches for vfs subclasses
These were flagged by PyCharm. I'm not sure why pytype doesn't catch these-
only `hgext/lfs/__init__.py` in the lfs extension is excluded from being
checked.
I'm not sure if the `*insidef` arg to `join()` was meant as an internal
convencience, because I see another class that gets flagged for the same
signature problem (to be fixed next). But I don't feel bold enough to make this
an internal function, and provide a simplified public `join()` on the `vfs`
classes. That can still be done later, if desired. For now, process the
additional args and pass them along, even though there don't appear to be any
current callers that provide extra args to these classes. We need all of the
subclasses to agree on the signature, or they won't be considered to implement
the `Vfs` protocol being developed.
While we're copy/pasting from the base class, bring the type annotations along
for the ride.
{
"conduit_uri": "https://phab.mercurial-scm.org/api",
"phabricator.uri": "https://phab.mercurial-scm.org/",
"repository.callsign": "HG",
"arc.land.onto.default": "@",
"base": "hg:.^"
}