refactor: add src_bank attribute to Payment and Topup model 🔨

billing/models.py

@@ -17,6 +17,7 @@ class Payment(models.Model):
     ]
     id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
     mib_reference = models.CharField(default="", null=True, blank=True)
+    source_bank = models.CharField(default="", null=True, blank=True)
     number_of_months = models.IntegerField()
     amount = models.FloatField()
     paid = models.BooleanField(default=False)
@@ -86,6 +87,7 @@ class Topup(models.Model):
         default="PENDING",
     )
     mib_reference = models.CharField(default="", null=True, blank=True)
+    source_bank = models.CharField(default="", null=True, blank=True)
     expires_at = models.DateTimeField(null=True, blank=True)
     expiry_notification_sent = models.BooleanField(default=False)
     created_at = models.DateTimeField(default=timezone.now)