This new LCEVC decoder plugin is meant to implement all LCEVC decoder elements.
For now, it only implements the LCEVC enhancement decoder (lcevcdec) element.
This element essentially enhances raw video frames using the LCEVC metadata
attached to input buffers into a higher resolution frame. The element is only
meant to be used after any base decoder (eg avdec_h264).
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7330>
