Add option to switch between full screen editor and old sidebar editor

Is your feature request related to a problem? Please describe.

After upgrading I was surprised to see the sidebar changed to fullscreen, and I really don't like it. It's way to abrupt of a change from a colourful calender to a mostly empty white page and then back to colourful and I can't see the other events while adding/editing which would be really handy.
Is it possible to make it an option to re-enable the sidebar in the settings? I was really surprised that that isn't an option already, as it's the perfect in-between of the simple editor [which is missing options] and the full-screen editor [which overwhelms the entire screen and blocks everything else].
To be fair it is practical sometimes, so I'd like to be able to choose in those scenarios.
Thank you for your continued development!

Describe the solution you'd like

An option in the setting to choose between sidebar/fullscreen editor.
Maybe additionally a button that "expands" the sidebar to the fullscreen editor when more space is needed (many invitees or long description), and the other way round to "shrink" to the side when you want to see the other events without having to close the editor?

Describe alternatives you've considered

Having a second tab open to switch to, to see the events while the editor is open (takes a while to sync with the edits on the other tab)
Using an external calendar program, which would be very impractical.

Additional context

I have read through #5513 and saw no mention of making it a setting/toggle-able, which is why I'm asking since there is no clear yes/no on this.

The issue names no files or tests. Start by reviewing the existing full-screen and sidebar editors referenced through #5513, then locate where editor display settings are handled. Done means users can choose the sidebar or full-screen editor, with the optional expand and shrink behavior clarified before implementation.