feat: add tenant api of create & delete user (#2204)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

### Type of change

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

api/apps/tenant_app.py

@@ -13,11 +13,17 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
+
+from flask import request
 from flask_login import current_user, login_required
 
-from api.utils.api_utils import server_error_response
+from api.db import UserTenantRole, StatusEnum
+from api.db.db_models import UserTenant
 from api.db.services.user_service import TenantService, UserTenantService
-from api.utils.api_utils import get_json_result
+from api.settings import RetCode
+
+from api.utils import get_uuid
+from api.utils.api_utils import get_json_result, validate_request, server_error_response
 
 
 @manager.route("/list", methods=["GET"])
@@ -29,6 +35,7 @@ def tenant_list():
     except Exception as e:
         return server_error_response(e)
 
+
 @manager.route("/<tenant_id>/user/list", methods=["GET"])
 @login_required
 def user_list(tenant_id):
@@ -37,3 +44,42 @@ def user_list(tenant_id):
         return get_json_result(data=users)
     except Exception as e:
         return server_error_response(e)
+
+
+@manager.route('/<tenant_id>/user', methods=['POST'])
+@login_required
+@validate_request("user_id")
+def create(tenant_id):
+    user_id = request.json.get("user_id")
+    if not user_id:
+        return get_json_result(
+            data=False, retmsg='Lack of "USER ID"', retcode=RetCode.ARGUMENT_ERROR)
+
+    try:
+        user_tenants = UserTenantService.query(user_id=user_id, tenant_id=tenant_id)
+        if user_tenants:
+            uuid = user_tenants[0].id
+            return get_json_result(data={"id": uuid})
+
+        uuid = get_uuid()
+        UserTenantService.save(
+            id = uuid,
+            user_id = user_id,
+            tenant_id = tenant_id,
+            role = UserTenantRole.NORMAL.value,
+            status = StatusEnum.VALID.value)
+
+        return get_json_result(data={"id": uuid})
+    except Exception as e:
+        return server_error_response(e)
+
+
+@manager.route('/<tenant_id>/user/<user_id>', methods=['DELETE'])
+@login_required
+def rm(tenant_id, user_id):
+    try:
+        UserTenantService.filter_delete([UserTenant.tenant_id == tenant_id, UserTenant.user_id == user_id])
+        return get_json_result(data=True)
+    except Exception as e:
+        return server_error_response(e)
+