Menu bar layout editor improvements

Hi,

it would be great if the window/view to edit a menu bar layout allowed me to remove/delete an item from the layout again (at least until BTT detects it again on the next launch), so I can get rid of the items that belong to apps I've deleted already.

Additionally, it might be nice to have the ability to create some sort of collapsible (and named) groups in the layout editor; those wouldn't change anything about the menu bar, the items or the layout, but be purely for better organization in the BTT layout editor (it can be a bit of a pain currently to reorder items as the list grows, collapsible groups would solve that and allow for a better overview). Maybe there's some alternative solution to that though, I'm open for anything that makes my current list of approx 80 items easier to manage/reorder :smiley: