[wpe-platform] Adding LG WPE patch for Wayland/Weston

[wouterlucas]

PR created on behalf of LGI. Patch is created by the LGI team to solve:

• Input device (IR/Keyboard/Mouse) doesn't work for WPE. But works for Weston.
• Video window is incorrect. Size of the video window is a contant value and position is random.
• WPE browser cannot be set to full screen due the issue Webrtcinwebkit merge #5.c.

[blino]

It would nice to have a configurable way to pass the default resolution to the view backend.
This would be useful for other backends as well.
The bcm-nexus backend currently uses a WPE_NEXUS_FORMAT environment variable.

Could we have a common API for all backends?
Maybe the size could be set into a wpe_view_backend property by WPELauncher ?

[zdobersek]

There's wpe_view_backend_dispatch_set_size(). How that is called depends on the backend, but it's not necessary for it to be called from the internal view backend implementation.