Summary: This interface provides a way for clients to create generic dmabuf-based wl_buffers.

Test Plan: Works with weston-simple-dmabuf-drm and weston-simple-dmabuf-egl in KWin.

Reviewers: #kwin, #plasma, graesslin, davidedmundson, mart, fredrik

Subscribers: zzag, kde-frameworks-devel, romangg, plasma-devel

Tags: #frameworks, #plasma_on_wayland

Maniphest Tasks: T8067

Differential Revision: https://phabricator.kde.org/D10747