Add event payload as event properties for the timeline view

Summary: Leverage the properties prop of `TimelineDataDescription`. Whenever an event is selected, the event payload is shown as the event properties.

Reviewed By: antonk52

Differential Revision: D44497058

fbshipit-source-id: 09782d583957a0df8c3efd3f5a62af6b321a26e3

desktop/plugins/public/ui-debugger/components/sidebar/Inspector.tsx

@@ -118,6 +118,7 @@ export const Inspector: React.FC<Props> = ({nodes, metadata}) => {
                     display: e.type.slice(e.type.lastIndexOf(':') + 1),
                     color: theme.primaryColor,
                     key: e.timestamp.toString(),
+                    properties: e.payload as any,
                   };
                 }),
                 current: '',