Add platform actions to configurations view

If you open lots of files in openHAB desginer you may loose the overview. Other eclipse IDEs provide the "Link with Editor" function in the project explorer. Another handy function in the project explorer in other eclipse IDEs is the "Collapse All" function. As I like both functions I thought I add them to the "Cofigurations" view.

I addition I fixed a capitalization issue in the "Select Configuration Folder" action.