JS frontend stuff

Move old ember frontend to properly named folder
Add vue based new frontend

frontend-reactive/app/components/util/multiselect.hbs

@@ -1,26 +0,0 @@
-<div class={{@wrapper-class}}>
-  {{#if @readonly}}
-    <ul>
-      {{#each this.args.elements as |element|}}
-        {{#if element.checked}}
-          <li>
-            <p>{{element.name}}</p>
-          </li>
-        {{/if}}
-      {{/each}}
-    </ul>
-  {{else}}
-    {{#each this.args.elements as |element|}}
-      <label class={{@label-class}}>
-        {{element.description}}
-        <Input
-          @type="checkbox"
-          name="{{element.name}}"
-          class="{{@input-classes}}"
-          @checked={{element.checked}}
-          {{on "change" this.onChange}}
-        />
-      </label>
-    {{/each}}
-  {{/if}}
-</div>