Add select course upon student bulk import, search field for students

cntmanage/flightslot/models/students.py

@@ -48,6 +48,12 @@ class Student(models.Model):
 
     def default_password(self) -> str:
         return f"{self.name.lower()[0]}{self.surname.lower()}{self.id}"
+    
+    def default_username(self) -> str:
+        if self.pk and self.user:
+            return self.user.username
+        else:
+            return ""
 
     # Override save method to add user for login upon Student creation
     def save(self, *args, **kwargs):