Allow setting of caseworking on a user

This commit changes the form that the user sees when inviting or editing
another user, if the service has the ‘caseworking’ permission set.

This will allow creating a new type of user, one who only has the
`send_messages` permission, without the `view_activity` permission.

We are doing this because we think there are a number of services with a
lot of users who don’t need to see the dashboard, or the other team
members, and that we can make a simpler interface for these users.

gulpfile.babel.js

@@ -73,6 +73,7 @@ gulp.task('javascripts', () => gulp
     paths.src + 'javascripts/errorTracking.js',
     paths.src + 'javascripts/preventDuplicateFormSubmissions.js',
     paths.src + 'javascripts/fullscreenTable.js',
+    paths.src + 'javascripts/conditionalRadios.js',
     paths.src + 'javascripts/main.js'
   ])
   .pipe(plugins.prettyerror())