Move ~/issuable_bulk_update_sidebar and other issuable code

...issuable/bulk_update_sidebar/components/status_select.vue

...ets/javascripts/issuable/bulk_update_sidebar/constants.js

.../issuable/bulk_update_sidebar/init_issue_status_select.js

...uable/bulk_update_sidebar/issuable_bulk_update_actions.js

...uable/bulk_update_sidebar/issuable_bulk_update_sidebar.js

.../bulk_update_sidebar/issuable_init_bulk_update_sidebar.js

...ripts/issuable/bulk_update_sidebar/subscription_select.js

app/assets/javascripts/issuable/init_issuable_sidebar.js

app/assets/javascripts/issuable/issuable_context.js

app/assets/javascripts/issuable/issuable_form.js

app/assets/javascripts/issuable/issuable_index.js

...ts/javascripts/issues_list/components/issues_list_app.vue

app/assets/javascripts/labels_select.js

...ets/javascripts/merge_conflicts/merge_conflicts_bundle.js

app/assets/javascripts/pages/groups/issues/index.js

app/assets/javascripts/pages/groups/merge_requests/index.js

app/assets/javascripts/pages/projects/issues/form.js

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

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

.../javascripts/pages/projects/merge_requests/index/index.js