Closes #13309: Introduce the account app (#13310)

* Introduce 'accounts' app for user-specific views & resources
* Move UserTokenTable to account app
* Move login & logout views to account app

netbox/account/models.py

@@ -0,0 +1,15 @@
+from django.urls import reverse
+
+from users.models import Token
+
+
+class UserToken(Token):
+    """
+    Proxy model for users to manage their own API tokens.
+    """
+    class Meta:
+        proxy = True
+        verbose_name = 'token'
+
+    def get_absolute_url(self):
+        return reverse('account:usertoken', args=[self.pk])