Implement wl_eglstream_controller Server Interface

Summary:
This implements a wrapper class for the wl_eglstream_controller Wayland
interface. It allows clients to inform the compositor when a new EGL Stream has
been created with an Wayland surface attached as its producer. The compositor
can then bind a GL texture as the stream's consumer allowing it access to the
surface's buffer contents for presentation. The only client currently expected
to make use of this interface is the NVIDIA EGL driver when running alongside a
compositor supporting EGLStream-based buffer sharing.

Reviewers: KWin, romangg, davidedmundson

Reviewed By: KWin, romangg, davidedmundson

Subscribers: kde-frameworks-devel

Tage: Frameworks

Differential Revision: https://phabricator.kde.org/D18824