[UI] Consider changing Properties -> Playback from a popup to a dropdown menu

Your idea

See title

Problem to be solved

The current Playback popup in the Properties panel is fairly impractical to use. It requires several clicks to open, and has numerous inconvenient behaviours which I believe are inherent to the popup format (it closes if you deselect the object by mistake, then doesn't reopen if you select it again). On the other hand, Playback properties are important and generic across many objects, so it can be rather difficult to understand why ‘tempo changes’ would be entitled to their own dropdown (which is a much more convenient format to use) and ‘Playback’ would not.

In addition, when you select a number of identical objects (fermata, hairpins, tempo changes...), they have their own dropdown menu named after themselves for their engraving properties. When several different items are selected, on the other hand, their engraving properties appear in the form of pop-ups under a single dropdown entitled ‘Notation’. So why don't the ‘Playback’ properties behave in the same way? It's actually the opposite behaviour, which is curious: a single ‘Playback’ popup with sub-dropdown menus entitled ‘Fermata’, ‘Tempo change’, etc. Normalising the behaviour would greatly benefit the ease of use of the software.

Prior art

No response

Additional context

Checklist

• This request follows the guidelines for reporting issues
• I have verified that this feature request has not been logged before, by searching the issue tracker for similar requests