reorganize packages, start converting overall app to react (very broken at the moment)

Packages/ohif-viewerbase/client/components/viewer/toolbarSectionButton/toolbarSectionButton.js

@@ -1,7 +1,7 @@
 import { OHIF } from 'meteor/ohif:core';
 import { Template } from 'meteor/templating';
 import { Session } from 'meteor/session';
-import { _ } from 'meteor/underscore';
+import _ from 'underscore';
 
 Template.toolbarSectionButton.onCreated(() => {
     const instance = Template.instance();