* Add failing test for copy->paste not being idempotent
* Ensure all elements on default skins use fixed anchors
`UsesFixedAnchor` defaults to false, i.e. closest anchors. Combined with
manual anchor / origin specs on some drawables, this would get default
skins into impossible states wherein a drawable would use "closest
anchor" but also explicitly specify anchor / origin that aren't closest,
which horribly fails on attempting to copy and paste.
Frankly shocked this has gone unnoticed for this long, and I regret not
vetoing this "feature" more every time I see its tentacles spread to
produce breakage of levels yet unseen.
Does this commit contain major levels of suck? For sure. Do I have any
better ideas that wouldn't consist of a multi-day rewrite or deletion of
this "feature"? No.
* Fix skin editor always applying closest anchor / origin on paste regardless of whether the component uses fixed anchor
Self-explanatory. Should close https://github.com/ppy/osu/issues/29111
along with previous commit.
More or less covers the first page of client sentry issues sorted by
volume, all of which is pretty much useless for anything because it's
client-specific-failure noise.