Refactor: user views and URLs

This commit refactors the user views and URLs in the backend. The `LoginView` function has been renamed to `login`, and the `RegisterUser` function has been renamed to `register_user`. The corresponding changes have also been made in the `urls.py` file. This improves code readability and follows naming conventions.

backend/api/urls.py

@@ -1,10 +1,10 @@
 from django.urls import path
 
-from users.views import LoginView, RegisterUser
+from users.views import login, register_user
 from documents.views import upload_pdf
 
 urlpatterns = [
-    path("create-user/", RegisterUser, name="create-user"),
-    path("login/", LoginView, name="login"),
+    path("create-user/", register_user, name="create-user"),
+    path("login/", login, name="login"),
     path("upload/", upload_pdf, name="upload"),
 ]

backend/users/views.py

@@ -39,7 +39,7 @@
     responses={200: login_success_response, 401: login_error_response},
 )
 @api_view(["POST"])
-def LoginView(request):
+def login(request):
     username = request.data.get("username")
     password = request.data.get("password")
     user = authenticate(username=username, password=password)
@@ -87,7 +87,7 @@ def LoginView(request):
     responses={201: register_success_response, 400: register_error_response},
 )
 @api_view(["POST"])
-def RegisterUser(request):
+def register_user(request):
     serializer = RegisterSerializer(data=request.data)
     if serializer.is_valid():
         serializer.save()