Move base64_image related functions to common directory (#10957)

### What problem does this PR solve?

As title

### Type of change

- [x] Refactoring

---------

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

rag/flow/hierarchical_merger/hierarchical_merger.py

@@ -21,7 +21,7 @@ from functools import partial
 import trio
 
 from common.misc_utils import get_uuid
-from api.utils.base64_image import id2image, image2id
+from common.base64_image import id2image, image2id
 from deepdoc.parser.pdf_parser import RAGFlowPdfParser
 from rag.flow.base import ProcessBase, ProcessParamBase
 from rag.flow.hierarchical_merger.schema import HierarchicalMergerFromUpstream

rag/flow/parser/parser.py

@@ -27,7 +27,7 @@ from api.db.services.file2document_service import File2DocumentService
 from api.db.services.file_service import FileService
 from api.db.services.llm_service import LLMBundle
 from common.misc_utils import get_uuid
-from api.utils.base64_image import image2id
+from common.base64_image import image2id
 from deepdoc.parser import ExcelParser
 from deepdoc.parser.mineru_parser import MinerUParser
 from deepdoc.parser.pdf_parser import PlainParser, RAGFlowPdfParser, VisionParser

rag/flow/splitter/splitter.py

@@ -18,7 +18,7 @@ from functools import partial
 import trio
 
 from common.misc_utils import get_uuid
-from api.utils.base64_image import id2image, image2id
+from common.base64_image import id2image, image2id
 from deepdoc.parser.pdf_parser import RAGFlowPdfParser
 from rag.flow.base import ProcessBase, ProcessParamBase
 from rag.flow.splitter.schema import SplitterFromUpstream