server specific js + sync all theme versions btn

app/assets/javascripts/server.js

app/assets/javascripts/server/websites.js

app/assets/javascripts/server/websites/batch-sync-themes.js

app/controllers/server/websites_controller.rb

app/views/server/layouts/application.html.erb

app/views/server/websites/manage_versions.html.erb

config/locales/en.yml

config/locales/fr.yml

config/routes/server.rb