Add feature : add chromadb support as a vector database

Author: powerli2002

modelcache/manager/vector_data/chroma.py

@@ -89,5 +89,4 @@ def flush(self):
         pass
 
     def close(self):
-        # chroma无flush方法
         pass

modelcache_mm/manager/vector_data/chroma.py

@@ -19,7 +19,6 @@ def __init__(
             persist_directory="./chromadb",
             top_k: int = 1,
     ):
-        # self.collection_name = "modelcache"
         self.top_k = top_k
 
         self._client = chromadb.PersistentClient(path=persist_directory)