Feat: Add hover tooltips to the UI

[ArthurBrussee]

The UI could do with some more tooltips.

The UI could also do with a cleanup pass in general

[Poly2it]

I'd say tooltips should not the primary way for UI-functionality to be presented to the user. Embedded descriptions or documentation in the interface, especially for complex options, makes the UI more approachable. Tooltips have a tendency to not be very legible, and rarely hold information about the full context of an element due to the tooltips' volatile nature in the interface.