Closes https://github.com/ppy/osu/issues/25239.
`LegacyEditorBeatmapPatcher.processHitObjectLocalData()` was already
supposed to be handling changes to hitobjects that will show up neither
when comparing the hitobjects themselves or the timing point with
"legacy" info stripped - so, in other words, changes to slider velocity
and samples.
However, a change to slider velocity requires default application to
take effect, so just resetting the value would visually fix the timeline
marker but not change the actual object. Calling
`EditorBeatmap.Update()` fixes this by way of triggering default
re-application.
This could probably be smarter (by only invoking the update when
strictly necessary, etc.) - but I'm not sure it's worth the hassle. This
is intended to be a quick fix, rather than a complete solution - the
complete solution would indeed likely entail a wholesale restructuring
of the editor's change handling.
`SelectionHandler` is receiving input from anywhere out of necessity:
19f892687a/osu.Game/Screens/Edit/Compose/Components/SelectionHandler.cs (L119-L125)
Also important is that `BlueprintContainer` will selectively not block
right clicks to make sure they fall through to the
`ContextMenuContainer`:
19f892687a/osu.Game/Screens/Edit/Compose/Components/BlueprintContainer.cs (L122-L126)
But because the whole editor is sharing a `ContextMenuContainer` and
it's at a higher level than both components, we observe here the
playfield's `SelectionHandler` intercepting the right click before it
can reach the `ContextMenuContainer`.
The fix here is similar to what we're already doing in
`TimelineBlueprintContaienr`.
I don't know what this test was trying to do, but it was wrong. Any
offset which is applied should be invisible to the clock's final
`CurrentTime` (and to the user).
This avoids it ever mutating the underlying track (aka attempting to start
it). Resolves the one caveat mentioned in
aeef92fa710648d4a00edc523e13c17ac6104125.
