LT-242: Sharing same timepoints source among all the sub-templates that use it

Packages/lesiontracker/client/components/flexboxLayout/flexboxLayout.html

@@ -1,10 +1,10 @@
 <template name="flexboxLayout">
     <div class="viewerSection">
         <div class="sidebarMenu sidebar-left {{#if leftSidebarOpen}}sidebar-open{{/if}}">
-            {{>studyTimepointBrowser}}
+            {{>studyTimepointBrowser (extend this)}}
         </div>
         <div class="mainContent {{#if leftSidebarOpen}}sidebar-left-open{{/if}} {{#if rightSidebarOpen}}sidebar-right-open{{/if}}">
-            {{>viewerMain}}
+            {{>viewerMain (extend this)}}
         </div>
         <div class="sidebarMenu sidebar-right {{#if or lesionSidebarOpen additionalFindingsSidebarOpen}}sidebar-open{{/if}}">
             <div class="sidebar-option {{#if lesionSidebarOpen}}active{{/if}}">