libcamera: buffer: Move captured metadata to FrameMetadata

Move the metadata retrieved when dequeuing a V4L2 buffer into a
FrameMetadata object. This is done as a step to migrate to the
FrameBuffer interface as the functions added to Buffer around
FrameMetadata match the ones in FrameBuffer.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

test/camera/capture.cpp

@@ -28,7 +28,7 @@ protected:
 
 	void bufferComplete(Request *request, Buffer *buffer)
 	{
-		if (buffer->status() != Buffer::BufferSuccess)
+		if (buffer->metadata().status != FrameMetadata::FrameSuccess)
 			return;
 
 		completeBuffersCount_++;