One of the current limitations of EGLStreams is that there's no way to
resize a surface consumer without re-creating the entire stream.

Therefore, while resizing, clients will send wl_surface::attach requests
so the compositor can re-create its endpoint of the stream, but no
buffer will be available actually. If we proceed with the rest of the
attach operation we'll be presenting an empty buffer.

In order to fix this, a separate wl_eglstream_controller protocol has
been introduced that clients can use to request a stream re-creation
without overloading wl_surface::attach for that purpose.

This change adds the required logic to create the corresponding
wl_eglstream_controller global interface that clients can bind to.

Whenever a client requests a stream to be created, we just need to
create and realize the new EGLStream buffer. The same buffer resource
will be given at a later time to wl_surface::attach, whenever new
content is ma...