refactor: port api/controllers/console/app/annotation.py api/controllers/console/explore/trial.py api/controllers/console/workspace/account.py api/controllers/console/workspace/members.py api/controllers/service_api/app/annotation.py to basemodel (#31833)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

api/fields/end_user_fields.py

@@ -1,4 +1,7 @@
-from flask_restx import Namespace, fields
+from __future__ import annotations
+
+from flask_restx import fields
+from pydantic import BaseModel, ConfigDict
 
 simple_end_user_fields = {
     "id": fields.String,
@@ -8,5 +11,18 @@ simple_end_user_fields = {
 }
 
 
-def build_simple_end_user_model(api_or_ns: Namespace):
-    return api_or_ns.model("SimpleEndUser", simple_end_user_fields)
+class ResponseModel(BaseModel):
+    model_config = ConfigDict(
+        from_attributes=True,
+        extra="ignore",
+        populate_by_name=True,
+        serialize_by_alias=True,
+        protected_namespaces=(),
+    )
+
+
+class SimpleEndUser(ResponseModel):
+    id: str
+    type: str
+    is_anonymous: bool
+    session_id: str | None = None