Fix PhoneNumberBanned producing status code 500 (#4570)

# What this PR does
Handle PhoneNumberBanned as status code 403 instead of 500

## Which issue(s) this PR closes

Closes [issue link here]

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## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] Added the relevant release notes label (see labels prefixed w/
`release:`). These labels dictate how your PR will
    show up in the autogenerated release notes.

---------

Co-authored-by: Joey Orlando <joey.orlando@grafana.com>

engine/apps/api/views/user.py

@@ -59,6 +59,7 @@ from apps.phone_notifications.exceptions import (
     FailedToStartVerification,
     NumberAlreadyVerified,
     NumberNotVerified,
+    PhoneNumberBanned,
     ProviderNotSupports,
 )
 from apps.phone_notifications.phone_backend import PhoneBackend
@@ -478,6 +479,8 @@ class UserView(
             phone_backend.send_verification_sms(user)
         except NumberAlreadyVerified:
             return Response("Phone number already verified", status=status.HTTP_400_BAD_REQUEST)
+        except PhoneNumberBanned:
+            return Response("Phone number has been banned", status=status.HTTP_403_FORBIDDEN)
         except FailedToStartVerification as e:
             return handle_phone_notificator_failed(e)
         except ProviderNotSupports:
@@ -505,6 +508,8 @@ class UserView(
             phone_backend.make_verification_call(user)
         except NumberAlreadyVerified:
             return Response("Phone number already verified", status=status.HTTP_400_BAD_REQUEST)
+        except PhoneNumberBanned:
+            return Response("Phone number has been banned", status=status.HTTP_403_FORBIDDEN)
         except FailedToStartVerification as e:
             return handle_phone_notificator_failed(e)
         except ProviderNotSupports: