Move api.settings to common.settings (#11036)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

---------

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

rag/utils/storage_factory.py

@@ -13,41 +13,3 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
-
-import os
-from enum import Enum
-
-from rag.utils.azure_sas_conn import RAGFlowAzureSasBlob
-from rag.utils.azure_spn_conn import RAGFlowAzureSpnBlob
-from rag.utils.minio_conn import RAGFlowMinio
-from rag.utils.opendal_conn import OpenDALStorage
-from rag.utils.s3_conn import RAGFlowS3
-from rag.utils.oss_conn import RAGFlowOSS
-
-
-class Storage(Enum):
-    MINIO = 1
-    AZURE_SPN = 2
-    AZURE_SAS = 3
-    AWS_S3 = 4
-    OSS = 5
-    OPENDAL = 6
-
-
-class StorageFactory:
-    storage_mapping = {
-        Storage.MINIO: RAGFlowMinio,
-        Storage.AZURE_SPN: RAGFlowAzureSpnBlob,
-        Storage.AZURE_SAS: RAGFlowAzureSasBlob,
-        Storage.AWS_S3: RAGFlowS3,
-        Storage.OSS: RAGFlowOSS,
-        Storage.OPENDAL: OpenDALStorage
-    }
-
-    @classmethod
-    def create(cls, storage: Storage):
-        return cls.storage_mapping[storage]()
-
-
-STORAGE_IMPL_TYPE = os.getenv('STORAGE_IMPL', 'MINIO')
-STORAGE_IMPL = StorageFactory.create(Storage[STORAGE_IMPL_TYPE])