Do more normalisation for better partial matching

Phone numbers sometimes contain stuff we normalise out. This matches
perfectly if we have a full phone number, because we can normalise the
thing we’re searching for in the same way as the search term.

With partial search terms we can’t do this completely, because we can’t
work out if ‘123’ is part of a UK number, an international number, the
start of the phone number, the last 3 digits, etc.

What we can do is remove some stuff that we can know will cause partial
search terms to not match:
- leading pluses
- leading `0`s
- any brackets
- any spaces

tests/app/dao/notification_dao/test_notification_dao.py

@@ -1766,6 +1766,41 @@ def test_dao_get_notifications_by_to_field_matches_partial_emails(sample_templat
     assert notification_2.id not in notification_ids
 
 
+@pytest.mark.parametrize('search_term', [
+    '001',
+    '100',
+    '09001',
+    '077009001',
+    '07700 9001',
+    '(0)7700 9001',
+    '4477009001',
+    '+4477009001',
+    pytest.mark.skip('+44077009001', reason='No easy way to normalise this'),
+    pytest.mark.skip('+44(0)77009001', reason='No easy way to normalise this'),
+])
+def test_dao_get_notifications_by_to_field_matches_partial_phone_numbers(
+    sample_template,
+    search_term,
+):
+
+    notification_1 = create_notification(
+        template=sample_template,
+        to_field='+447700900100',
+        normalised_to='447700900100',
+    )
+    notification_2 = create_notification(
+        template=sample_template,
+        to_field='+447700900200',
+        normalised_to='447700900200',
+    )
+    results = dao_get_notifications_by_to_field(notification_1.service_id, search_term)
+    notification_ids = [notification.id for notification in results]
+
+    assert len(results) == 1
+    assert notification_1.id in notification_ids
+    assert notification_2.id not in notification_ids
+
+
 @pytest.mark.parametrize('to', [
     'not@email', '123'
 ])