MAGN-4496 DUI: After click on member the node should appear at Node surface

Just creation of node. Nothing more.
@Benglin, please take a look.

Task on YouTrack: [MAGN-4496 DUI: After click on member the node should appear at Node surface](http://adsk-oss.myjetbrains.com/youtrack/issue/MAGN-4496)

Minor fixes required:

1. "sender" might not be "ListBoxItem", use "as" keyword and check for "null".
2. Rename "fromSender" as "listBoxItem".
3. Use "var listBoxItem" instead of "ListBoxItem listBoxItem" for simplicity.
4. Use "var searchElement" instead of "SearchElementBase searchEle".
5. Check for "null" before dereferencing anything that can be "null".