Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
- Gemfile
- app/controllers/api/v1/search_controller.rb
  Conflict because we changed the number of default results to be
  configurable
- app/lib/settings/scoped_settings.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)
- spec/controllers/application_controller_spec.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)

app/views/about/_login.html.haml

@@ -1,4 +1,4 @@
-= simple_form_for(new_user, url: user_session_path) do |f|
+= simple_form_for(new_user, url: user_session_path, namespace: 'login') do |f|
   .fields-group
     - if use_seamless_external_login?
       = f.input :email, placeholder: t('simple_form.labels.defaults.username_or_email'), input_html: { 'aria-label' => t('simple_form.labels.defaults.username_or_email') }, hint: false

app/views/about/_registration.html.haml

@@ -1,4 +1,4 @@
-= simple_form_for(new_user, url: user_registration_path) do |f|
+= simple_form_for(new_user, url: user_registration_path, namespace: 'registration') do |f|
   .simple_form__overlay-area
     %p.lead= t('about.federation_hint_html', instance: content_tag(:strong, site_hostname))