🍒 Grow PipeWireFrameData to replace QImage to store local frames

While it's handy because QImage can be rendered into, it's useful to us to be able to pass around the frame data without needing QImage to support it. This is necessary for KPipeWire to support processing (both rendering and recording) frames that aren't RGB textures and the likes, which is quite common in cameras. Instead of automatically copying the buffer, hand over to QImage the function to free the buffer so it can give it away when it's done with.

(cherry picked from commit 5c027038)