Move some enumerate type to constants.py (#10998)

### What problem does this PR solve?

As title.

### Type of change

- [x] Refactoring

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

api/apps/sdk/doc.py

@@ -43,7 +43,7 @@ from rag.nlp import rag_tokenizer, search
 from rag.prompts.generator import cross_languages, keyword_extraction
 from rag.utils.storage_factory import STORAGE_IMPL
 from common.string_utils import remove_redundant_spaces
-from common.contants import RetCode
+from common.constants import RetCode
 
 MAXIMUM_OF_UPLOADING_FILES = 256