implement card reference widget, fix DeckIcon.vue

bring back eslint and stylelint on compilation, fix almost all warnings, ignore some

Signed-off-by: Julien Veyssier <eneiluj@posteo.net>

src/components/board/TimelineTabSidebar.vue

@@ -7,7 +7,7 @@
 </template>
 
 <script>
-import ActivityList from '../ActivityList'
+import ActivityList from '../ActivityList.vue'
 
 export default {
 	name: 'TimelineTabSidebar',