[misc][plugin] add plugin system implementation (#7426)

tests/distributed/test_distributed_oot.py

@@ -0,0 +1,6 @@
+from ..entrypoints.openai.test_oot_registration import (
+    run_and_test_dummy_opt_api_server)
+
+
+def test_distributed_oot(dummy_opt_path: str):
+    run_and_test_dummy_opt_api_server(dummy_opt_path, tp=2)