add video frame type and debug viewer and debug test source

the test source thread will always exist for now
the debug view will open a window for each connection

src/debug_video_tap.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <solanaceae/object_store/fwd.hpp>
+#include "./frame_streams/stream_manager.hpp"
+#include "./texture_uploader.hpp"
+
+// provides a sink and a small window displaying a SDLVideoFrame
+// HACK: provides a test video source
+class DebugVideoTap {
+	ObjectStore2& _os;
+	StreamManager& _sm;
+	TextureUploaderI& _tu;
+
+	ObjectHandle _tap;
+	ObjectHandle _src;
+
+	public:
+		DebugVideoTap(ObjectStore2& os, StreamManager& sm, TextureUploaderI& tu);
+		~DebugVideoTap(void);
+
+		float render(void);
+};
+