Set org type to NHS if user has NHS email address

We get people signing up for Notify who work for the NHS, but whose
organisation we don’t know about. For example
`name@gloshospitals.nhs.uk` will be someone working for Gloucestershire
Hospitals NHS Foundation Trust, which is not an organisation we have in
the database.

Currently we rely on knowing the specific organisation (NHS as a whole
isn’t an organisation) in order to set the organisation type for any
services they create. This commit adds a special case for anyone with an
NHS email address to set the organisation type to be NHS, even when we
don’t know which specific part of the NHS they work for.

This is the same thing we do on the API side for NHS email and letter
branding:
a4ae5a0a90/app/dao/services_dao.py (L310-L313)

app/models/user.py

@@ -205,6 +205,20 @@ class User(UserMixin):
             organisations_client.get_organisation_by_domain(self.email_domain)
         )
 
+    @property
+    def default_organisation_type(self):
+        if self.default_organisation:
+            return self.default_organisation.organisation_type
+        if self.has_nhs_email_address:
+            return 'nhs'
+        return None
+
+    @property
+    def has_nhs_email_address(self):
+        return self.email_address.lower().endswith((
+            '@nhs.uk', '.nhs.uk', '@nhs.net', '.nhs.net',
+        ))
+
     def serialize(self):
         dct = {
             "id": self.id,