[X11] Switch from `DllImport`s to `LibraryImport`s for better performance

[Youssef1313]

What would you like to be added

All bindings should be switched to LibraryImport:

https://github.com/unoplatform/uno/blob/2ea1c54b08f22b37e7a5ebf73d3049c4538687f1/src/Uno.UI.Runtime.Skia.X11/X11_Bindings/x11bindings_Glx.cs https://github.com/unoplatform/uno/blob/2ea1c54b08f22b37e7a5ebf73d3049c4538687f1/src/Uno.UI.Runtime.Skia.X11/X11ApplicationHost.cs https://github.com/unoplatform/uno/blob/2ea1c54b08f22b37e7a5ebf73d3049c4538687f1/src/Uno.UI.Runtime.Skia.X11/X11_Bindings/x11bindings_XLib.cs https://github.com/unoplatform/uno/blob/2ea1c54b08f22b37e7a5ebf73d3049c4538687f1/src/Uno.UI.Runtime.Skia.X11/X11_Bindings/X11Helper.cs

Why is this needed

No response

For which platform

No response

Anything else we need to know?

No response

[ramezgerges]

I have quite a few X11 PRs open, so let's put this one on hold until they merge so I don't have to deal with a million conflicts.