Feat(API): CRUD functionalities with todo items

- wrote tests for todo items workflow

backend/tests/blueprints/test_todos.py

@@ -0,0 +1,54 @@
+from quart import Quart
+
+
+async def test_post_todo(app: Quart) -> None:
+    test_client = app.test_client()
+    async with test_client.authenticated("1"):  # type: ignore
+        response = await test_client.post(
+            "/todos/",
+            json={"complete": False, "due": None, "task": "Test task"},
+        )
+        assert response.status_code == 201
+        assert (await response.get_json())["id"] > 0
+
+
+async def test_get_todo(app: Quart) -> None:
+    test_client = app.test_client()
+    async with test_client.authenticated("1"):  # type: ignore
+        response = await test_client.get("/todos/1/")
+        assert response.status_code == 200
+        assert (await response.get_json())["task"] == "Test Task"
+
+
+async def test_put_todo(app: Quart) -> None:
+    test_client = app.test_client()
+    async with test_client.authenticated("1"):  # type: ignore
+        response = await test_client.post(
+            "/todos/",
+            json={"complete": False, "due": None, "task": "Test task"},
+        )
+        todo_id = (await response.get_json())["id"]
+
+        response = await test_client.put(
+            f"/todos/{todo_id}/",
+            json={"complete": False, "due": None, "task": "Updated"},
+        )
+        assert (await response.get_json())["task"] == "Updated"
+
+        response = await test_client.get(f"/todos/{todo_id}/")
+        assert (await response.get_json())["task"] == "Updated"
+
+
+async def test_delete_todo(app: Quart) -> None:
+    test_client = app.test_client()
+    async with test_client.authenticated("1"):  # type: ignore
+        response = await test_client.post(
+            "/todos/",
+            json={"complete": False, "due": None, "task": "Test task"},
+        )
+        todo_id = (await response.get_json())["id"]
+
+        await test_client.delete(f"/todos/{todo_id}/")
+
+        response = await test_client.get(f"/todos/{todo_id}/")
+        assert response.status_code == 404