mpv needs 'gpu-context=wayland' for proper fullscreen support

[EFrMG]

System details

Intel Core i3-8130U; UHD Graphics 620; Omarchy 3.3.3

What's wrong?

Default mpv configuration

For mpv to render correctly on wayland while on fullscreen, one needs to add gpu-context=wayland to its config.
This happens because of mpv defaulting to a faulty way for the GPU to manage the image, which Wayland sets on it correctly while not on fullscreen.

Demonstration

I have here a visual demonstration of this, where one can appreciate the pastel colors on monkeytype being barely distinct from each other:

Without the config fix

And with the fix applied

The screenshots were taken at roughly the same frame, yet are not edited in any manner.
The image could seem washed away, so to speak.

How I intend to contribute

I have made the following changes expressed in a future PR.

• Created a config file with just that one line at config/
• Added a unix-timestamped migration script at migrations/ that does:
  • Check if the file exists and copies it from config/ otherwise.
  • If incorrect lines setting the same property exist, deletes them.
  • If the line is not there then, checks if to add a newline and adds the simple line in question.

[dhh]

Discussion continues in PR.