added internal notes and improved invite link form

cookbook/models.py

@@ -415,6 +415,9 @@ class UserSpace(models.Model, PermissionModelMixin):
     # that having more than one active space should just break certain parts of the application and not leak any data
     active = models.BooleanField(default=False)
 
+    invite_link = models.ForeignKey("InviteLink", on_delete=models.PROTECT, null=True, blank=True)
+    internal_note = models.TextField(blank=True, null=True)
+
     created_at = models.DateTimeField(auto_now_add=True)
     updated_at = models.DateTimeField(auto_now=True)
 
@@ -1144,6 +1147,8 @@ class InviteLink(ExportModelOperationsMixin('invite_link'), models.Model, Permis
     created_by = models.ForeignKey(User, on_delete=models.CASCADE)
     created_at = models.DateTimeField(auto_now_add=True)
 
+    internal_note = models.TextField(blank=True, null=True)
+
     space = models.ForeignKey(Space, on_delete=models.CASCADE)
     objects = ScopedManager(space='space')