Feature/copy paste delete

Adds a method to copy, paste, and delete.

To copy: Highlight a test case. press the menu button or CMD-C. 

To Paste: Go to new category, press CMD-V or menu button to paste test case.

To Delete: Highlight testcase, press CMD-D or hit menu button OR hit the icon :)

New! Create new category : CMD-SHIFT-N!
New! Sync With Cloud menu item : CMD-R


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Changes Delete test case short cut to backspace.
Changes Delete Category shortcut to CMD-backspace