This PR shows conflicts in a user's keymap editor by adding an error
background to a conflicting row and allows users to filter the keymap
editor by conflicts.

A key binding is determined to have a conflict if any other binding has
the same context and key strokes. In the future, this could be further
improved upon by normalizing bindings’ context so it's not just a string
comparison.


Release Notes:

- N/A

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Co-authored-by: MrSubidubi <dev@bahn.sh>