Vue Store (#8071)

* vue: use our own store in place of vuex

* vue store: add getters, watcher and use internal vue instance

* vue store: better state getter and credits to Vuex

* vue store: $watch -> watch

* vuex store: pass store to getters and fix typos

* add comments to store, start writing tests

* fix unit tests and add missing ones

* cleanup components, add less folder, fetch tassks

* use Vuex helpers

* pin vuex version

* move semantic-ui theme to assets/less, keep website/build empty but in git

* import helpers from vuex

website/client/components/appHeader.vue

@@ -0,0 +1,24 @@
+<template lang="pug">
+#app-header
+  h1 {{title}}
+  ul
+    li
+      router-link(to='/') Home
+    li
+      router-link(to='/page') Another Page
+</template>
+
+<script>
+import { mapState } from '../store';
+
+export default {
+  computed: mapState(['title']),
+};
+</script>
+
+<!-- Add "scoped" attribute to limit CSS to this component only -->
+<style scoped>
+h1 {
+  color: #42b983;
+}
+</style>