v2.4.1 — replaced and ignored tags come off

A fix for libraries that replace their genres. Upgrading is a pull, followed by one
forced run of each library that uses "Replace existing genres".

Replaced and ignored tags stayed in Plex

With "Replace existing genres" (clearGenres) on, names covered by a rename or an
ignore rule could stay on an item after a run. The rules were applied; the write was
not what it should have been.

Plex's library listing returns only the first few tags of each item, typically two
genres of four, and every write was planned from that listing. The tags to take off
were therefore only the ones it showed: every older tag past the cut stayed on the
item, which is exactly where a renamed or ignored name tends to sit once a library
writes keywords. An item whose visible tags already matched was even reported as
unchanged.

A write that takes tags off now reads the item's own page first. That covers
"Replace existing genres", names refused by hand, and names added by hand. A write
that only adds does not need to, because Plex appends: merging libraries and rating
collections cost no extra request.

The Genres… dialog reads the item's full list too. The list it showed came from
the same listing, and fixing an item's genres from it would have dropped the ones it
did not show.

After upgrading

Items written by an earlier version keep their hidden tags until they are written
again, and the cache has no reason to rewrite them. Run each affected library once
with Force (the console's Run menu), or:

plex-auto-genres run --library "<library>" --force