Linux clipboard support in `ironrdp-cliprdr-native`/`ironrdp-client`

[pacmancoder]

Add support for the native clipboard for Linux clients in ironrdp-cliprdr-native/ironrdp-client.
See existing Windows and ironrdp-web implementation for reference.

Notes

We could focus on X11 API support as a first step -- Wayland should provide some compatibility with X11 via Xwayland, therefore we could cover more systems by implementing X11 backend first, and then add Wayland support later (if needed at all).

(cc @CBenoit -- Please validate is my assumption regarding X11/Wayland correct?)

[CBenoit]

(cc @CBenoit -- Please validate is my assumption regarding X11/Wayland correct?)

This sounds right to me!