Wayland support on Linux

Many Unix-like platforms are in the process of adopting the more modern Wayland protocol in place of X11, so it would be great to have native Wayland support in the RenderDoc in-application API. Currently, both RenderDoc and the games need to be launched using the XWayland compatibility layer to work properly, which is a bit irritating.

Introducing support for Wayland would require the following changes:

1. DevicePointer should support an EGLSurface (seems like issue #253 is relevant here).
2. WindowHandle should support a wl_surface.