Continuation of #5713
**Silently breaking changes:**
- Menus now close on click by default, this is configurable via
`PopupCloseBehavior`
**Additional additions:**
- `Button::right_text`
- `StyleModifier`
This is a rewrite of the egui menus, with the following goals:
- submenu buttons should work everywhere, in a popup, context menu,
area, in some random Ui
- remove the menu state from Ui
- should work just like the previous menu
- ~proper support for keyboard navigation~
- It's better now but requires further work to be perfect
- support `PopupCloseBehavior`
* Closes#4607
* [x] I have followed the instructions in the PR template
lucasmerlin