Feat: Alter flask to Quart for async API serving. (#11275)

### What problem does this PR solve?

#11277

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

agent/canvas.py

@@ -25,7 +25,6 @@ from typing import Any, Union, Tuple
 
 from agent.component import component_class
 from agent.component.base import ComponentBase
-from api.db.services.file_service import FileService
 from api.db.services.task_service import has_canceled
 from common.misc_utils import get_uuid, hash_str2int
 from common.exceptions import TaskCanceledException
@@ -284,7 +283,7 @@ class Canvas(Graph):
                 else:
                     self.globals[k] = None
 
-    def run(self, **kwargs):
+    async def run(self, **kwargs):
         st = time.perf_counter()
         self.message_id = get_uuid()
         created_at = int(time.time())
@@ -549,6 +548,7 @@ class Canvas(Graph):
         return self.components[cpnnm]["obj"].get_input_elements()
 
     def get_files(self, files: Union[None, list[dict]]) -> list[str]:
+        from api.db.services.file_service import FileService
         if not files:
             return  []
         def image_to_base64(file):