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>

agent/test/client.py

@@ -16,7 +16,7 @@
 import argparse
 import os
 from agent.canvas import Canvas
-from api import settings
+from common import settings
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser()