Supersedes https://github.com/ppy/osu/pull/29196.
Addresses https://github.com/ppy/osu/discussions/24384.
`SelectionHandler` is receiving input from anywhere out of necessity: https://github.com/ppy/osu/blob/19f892687a0607afbe4e0d010366dc2a66236073/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`: https://github.com/ppy/osu/blob/19f892687a0607afbe4e0d010366dc2a66236073/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`.
TimelineArea
BeatDivisorControl
The result of https://github.com/ppy/osu/pull/20739 and https://github.com/ppy/osu/pull/20738 having unintended side effects when applied together.
OnTimelineLoaded