[TC-221]: init template-backend-service (#1)

https://eva.avroid.tech/desk/cards?obj=Task:TC-221

Начальная версия сервиса-шаблона

Co-authored-by: Nadezhda <nadezhda.lavrentieva@avroid.team>
Reviewed-on: https://git.avroid.tech/Templates/template-backend-service/pulls/1
Reviewed-by: Victor Stratov <victor.stratov@avroid.tech>

src/models/base.py

@@ -0,0 +1,20 @@
+from enum import Enum
+from uuid import UUID
+
+from pydantic import BaseModel
+
+
+class RoleEnum(Enum):
+    admin = 1
+    manager = 2
+    client = 3
+
+
+class Messenger(BaseModel):
+    chat_id: UUID
+    title: str | None = None
+
+
+class MessengerHandbookCountry(BaseModel):
+    country_id: int
+    iso_3166_code_alpha3: str | None = None