feat: videoplayback proxying

adds support for proxying videos through the instance
the support is configurable, and disabled by default

ythdd.py

@@ -67,6 +67,7 @@ def setup():
 	app.add_url_rule('/ggpht/<path:received_request>', view_func=views.ggphtProxy)
 	app.add_url_rule('/guc/<path:received_request>', view_func=views.gucProxy)
 	app.add_url_rule('/img/<path:received_request>', view_func=views.imgProxy)
+	app.add_url_rule('/videoplayback', view_func=views.videoplaybackProxy)
 	db = ythdd_db.initDB(app, config)
 
 	with app.app_context():
@@ -134,7 +135,7 @@ def main(args):
 	app_port = port
 
 	setup()
-	app.run(host=host, port=int(port))
+	app.run(host=host, port=int(port), threaded=True)
 
 if __name__ == "__main__":
 	#app.run(host="127.0.0.1", port=5000)