LPS-43263 Clicking Content, Applications, or Page in the Add menu wil…

Hey @jonmak08

The code I removed from both of these files were duplicated in the other, total copies.

I left _onPortletClose() in dockbar_add_application.js because that file handles the adding and removal of portlets from the applications tab, and because it wasn't even working in the other file. I left _onShowTab() in dockbar_add_content.js because we are storing many other session_clicks in that file, so it fits.