LT-275: Creating 3 columns layout for open source version

Packages/lesiontracker/client/components/measureFlow/measureFlow.html

@@ -1,5 +1,5 @@
 <template name="measureFlow">
-    <div class="measure-flow {{instance.state.get}}" style="position:fixed; top:200px; left:400px">
+    <div class="measure-flow {{#if this.treeColumns}}tree-columns{{/if}} {{instance.state.get}}" style="position:fixed; top:200px; left:400px">
         <button class="btn-add">Add label</button>
         {{#if eq instance.state.get 'selected'}}
             <div class="tree-leaf">