Display data model in side panel

Summary:
This displays the data models passed to the Sections in the side panel when a data node is clicked. This does not change the collapse behaviour when a Section node is clicked.
To make it easier to associate a section with its changesets, appended the global indexes a Section is responsible for to the node label.

Reviewed By: passy

Differential Revision: D16283820

fbshipit-source-id: f1149f47dff448de05d919f7f8d16a2aba53bbb0

src/plugins/sections/Tree.js

@@ -66,6 +66,7 @@ type TreeData = Array<{
 
 type Props = {
   data: TreeData | SectionComponentHierarchy,
+  nodeClickHandler?: (node, evt) => void,
 };
 
 type State = {
@@ -227,6 +228,7 @@ export default class extends PureComponent<Props, State> {
                 },
               }}
               nodeSize={{x: 300, y: 100}}
+              onClick={this.props.nodeClickHandler}
             />
           )}
         </Container>