Move issues code out of ~/pages

...assets/javascripts/issues/filtered_search_service_desk.js

app/assets/javascripts/issues/form.js

...s/javascripts/issues/init_filtered_search_service_desk.js

app/assets/javascripts/issues/show.js

...assets/javascripts/pages/projects/incidents/show/index.js

app/assets/javascripts/pages/projects/issues/edit/index.js

app/assets/javascripts/pages/projects/issues/new/index.js

...s/javascripts/pages/projects/issues/service_desk/index.js

app/assets/javascripts/pages/projects/issues/show/index.js

ee/app/assets/javascripts/issues/form.js

...pp/assets/javascripts/pages/projects/issues/show/index.js