Move some functions out of 'api/utils/common.py' (#10948)

### What problem does this PR solve?

as title.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

rag/utils/es_conn.py

@@ -28,7 +28,7 @@ from rag import settings
 from rag.settings import TAG_FLD, PAGERANK_FLD
 from common.decorator import singleton
 from common.file_utils import get_project_base_directory
-from api.utils.common import convert_bytes
+from common.misc_utils import convert_bytes
 from rag.utils.doc_store_conn import DocStoreConnection, MatchExpr, OrderByExpr, MatchTextExpr, MatchDenseExpr, \
     FusionExpr
 from rag.nlp import is_english, rag_tokenizer