Sessions can now be retrieved from a backend in a more general manner.
Multi-backend gets back its `session` field that contains the session
if one was created, removing the interfacing from multi backend with the
drm backend directly. This adds the possibility to use sessions even
without the drm backend.
It additionally fixes the bug that 2 session objects got created when
WLR_BACKENDS were set to "libinput,drm".
To allow vt switching without drm backend (and drm fd) on logind, start
listening to PropertiesChanged signals from dbus and parse the session
"Active" property when no master fd was created (this does not change
current drm backend behaviour in any way).
* Ensure keysyms state is always updated
* Check if pressed keysyms are exactly the binding keysyms
* Do not include modifiers in list of keysyms, these are special cases
As mentioned in https://github.com/swaywm/wlroots/issues/393 keybinds
did't trigger / were checked with "odd" keys and modifiers.
This commit sends the keycode through two paths, one to get the keycode
and modifiers *after* xkb handles them, a secondary path to get a "raw"
keysym without modifiers and then add the modifiers rootston knows
about.
This will result in the `[Alt]+[Shift]+2` combination I mention earlier
going through the keybind detection twice.
1) `[Alt]+[at]`
2) `[Alt]+[Shift]+2`
When either combination is found, the appropriate keybind is executed.
The xkb handled version will be prefered over the "raw" version.