Client: async resources, make store reusable, move plugins and add getTaskFor getter (#8575)

Add library to manage async resource
Make Store reusable for easier testing
Move plugin to libs
Add getTaskFor getter with tests

website/client/components/inventory/index.vue

@@ -7,8 +7,4 @@
       router-link.nav-link(:to="{name: 'stable'}") {{ $t('stable') }}
   .col-12
     router-view
-</template>
-
-<script>
-export default {};
-</script>
+</template>