start work on implementing libdecor for csd

[shailpatels]

• By selecting this checkbox, I agree to license my contributions to this project under the license(s) described in the LICENSE file, and I have the right to do so or have received permission to do so by an employer or client I am producing work for whom has this right.

This PR introduces libdecor to the wayland backend to help render client side decorations. See this issue for more context: #1298

This is a screenshot of the core-triangle example running with client side decorations,

I'm testing on nixos with gnome mutter which does not support server side decorations, from the logs, the error:

error(mach): Server Side Decorations aren't supported

Falling back to X11

No longer shows!

Here is an example off falling back to ssd rendering if libdecor is not available:

This PR is a bit incomplete however, things like resizing are still wonky: (updated added back the code that attempts to recreate the swapchain but causes a segfault for me, if this is removed the behavior looks like the attached video: )
Screencast From 2025-02-18 11-45-01.webm

Other things I'm not sure about

• libdecor has a couple of plugins implemented for rendering decorations for different backends, it appears these are packaged with the library but I'm not sure if I need to dynamically load them for cross compilation or if there should be a way to select which plugin is used.
• Need to test server side rendering to make sure I didn't break that functionality
• Introduced an issue where a keyboard press causes a crash in libxkbcommon's interface This might of been an issue before my changes, it looks like the keyboard listener was not getting called before the core window would be written with null values for the xkb variables, causing a crash because wl.xkb_state was null when keyboardHandleKey was called, this appears to be fixed with another wl_display_roundtrip call which doesn't feel like a great solution, but no sure how else to handle this :/
• Currently client side decorations are always used if possible, need to implement a way for a user to request which mode, potentially through: https://wayland.app/protocols/xdg-decoration-unstable-v1#zxdg_toplevel_decoration_v1:event:configure?

This is also my first PR to mach so additional feedback / guidance is appreciated :)
Feel free to push changes to the fork as well!

[shailpatels]

CC: @RonaldZielaznicki