Draft: Recreate output on EDID change
Some displays change their EDID while connected. The EDID can also change if the user overrides it. With this change, a new EDID will take effect immediately after it changes.
This also refactors scan_drm_connectors
so that GPU hot-plug handling is now separate from display hot-plug handling. I haven't tested GPU hot-plug since I don't have any with an external GPU, but I decided to submit this as a draft in case other people find this useful.