more FA5 stuff with small related refactoring

src/App.scss

src/components/chat_panel/chat_panel.js

src/components/chat_panel/chat_panel.vue

src/components/exporter/exporter.js

src/components/exporter/exporter.vue

src/components/extra_buttons/extra_buttons.js

src/components/extra_buttons/extra_buttons.vue

src/components/media_upload/media_upload.vue

src/components/notification/notification.js

src/components/notification/notification.scss

src/components/notification/notification.vue

src/components/notifications/notifications.js

src/components/notifications/notifications.scss

src/components/notifications/notifications.vue

src/components/panel_loading/panel_loading.vue

src/components/popover/popover.vue

src/components/scope_selector/scope_selector.js

src/components/scope_selector/scope_selector.vue

src/components/search/search.js

src/components/search/search.vue