Our support ticket analysis shows that the most common action request
after going live is turning on letters.
We just do this for any team that requests it – there’s no gatekeeping.
So we should just allow people to make the change themselves.
This will be a better experience for our users, and less work for us.
The design of the page replicates roughly what we have for international
text messaging.
In pages specific to a service (e.g. dashboard and sub pages) the title
needs to distinguish which service it applies to. This is mainly to give
context to screen reader users who could be managing multiple services.
Implementing this uses template inheritance:
`page_title` includes `per_page_title` includes `service_page_title`
‘GOV.UK Notify’ is inserted into every page title.
Pages that set `service_page_title` get the service name inserted too.
