Option to minimize widgets by default everywhere

[turt2live]

I find them a bit intrusive and normally minimize them manually anyways. Would be nice to have them be collapsed by default in rooms.

[lampholder]

This suggests a bigger problem with them (why are they defaulting to maximised if that's not useful to everyone? Is it because we're not confident people would notice them in their minimised form? Is that something we could tackle?)

This might be okay as a short term sticking plaster, though it would probably end up being Yet Another option in user settings :\

[turt2live]

The larger issue is the widget takes a third of my screen, is much more visible than the timeline, flashes a lot while loading (on the dark theme), and doesn't finish loading until well after the room has been opened.

Starting widgets minimized fixes a lot of those issues while still keeping their usefulness.

[turt2live]

Closing in favour of #12921