This PR lightly refactors the `EditorMode::Full` exposing two new
methods: `is_full` and `set_mode`.

Motivation is to expose fields that modify the behavior when the editor
is in `Full` mode. By using is `mode.is_full()` instead of
`EditorMode::Full` we can introduce new fields without breaking other
places in the code.

Release Notes:

- N/A

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>