feat: guarantee extensions order

Author: xuhaidong

sea/app.py

@@ -137,7 +137,10 @@ def load_extensions_in_module(self, module):
         def is_ext(ins):
             return not inspect.isclass(ins) and hasattr(ins, "init_app")
 
-        for n, ext in inspect.getmembers(module, is_ext):
+        for n, ext in sorted(
+            inspect.getmembers(module, is_ext),
+            key=lambda x: getattr(x[1], "load_order", 0),
+        ):
             self._register_extension(n, ext)
         return self.extensions