display-settings: Unused possibilities of the wlr-output-management protocol on Wayland
Two things were left out of the Wayland port, because they don't have their X11 counterparts, but which could be useful in one way or another:
* [Custom mode](https://wayland.app/protocols/wlr-output-management-unstable-v1#zwlr_output_configuration_head_v1:request:set_custom_mode). One use comes to mind to address #18: instead of playing with scales as suggested there, simply set the largest output's custom mode to the smallest output's preferred mode. Not sure that adding the ability to set a custom mode in the UI is relevant though.
* [Adaptive sync](https://wayland.app/protocols/wlr-output-management-unstable-v1#zwlr_output_configuration_head_v1:request:set_adaptive_sync), aka Variable Refresh Rate or VRR. This could perhaps be added to the UI.
issue