feature(libinput): Add function to reset driver states

[Johennes]

This adds new functions to de-initialise the libinput and XKB driver states which allows existing data structures to be reused when devices are connected or disconnected at runtime.

An example of how to use this can be found in https://gitlab.com/cherrypicker/unl0kr/-/merge_requests/15.

[kisvegabor]

Thank you!