more FA5 stuff with small related refactoring

src/components/extra_buttons/extra_buttons.js

@@ -1,8 +1,24 @@
 import Popover from '../popover/popover.vue'
 import { library } from '@fortawesome/fontawesome-svg-core'
-import { faEllipsisH } from '@fortawesome/free-solid-svg-icons'
+import {
+  faEllipsisH,
+  faBookmark,
+  faEyeSlash,
+  faThumbtack,
+  faShareAlt
+} from '@fortawesome/free-solid-svg-icons'
+import {
+  faBookmark as faBookmarkReg,
+} from '@fortawesome/free-regular-svg-icons'
 
-library.add(faEllipsisH)
+library.add(
+  faEllipsisH,
+  faBookmark,
+  faBookmarkReg,
+  faEyeSlash,
+  faThumbtack,
+  faShareAlt
+)
 
 const ExtraButtons = {
   props: [ 'status' ],