Replaced use of deprecated BinaryFunction et al with BiFunction et al

Replaced use of deprecated BinaryFunction et al with BiFunction et al

Also added missing logic to GraphExplorerComposite.SelectionElement to
discover Resource from Variable when WorkbenchSelectionElement is asked
for AnyResource. This is part of the fix for #7116.

Fixed breakage from ContextualHelp F1 keystroke handler which was
introduced in the original SVN commit r32734 (#6446).

refs #7116
refs #7117

Change-Id: Ia7c88d2c1b274fd788a0a18d95c2f059cea36086
(cherry picked from commit e84008c029ef2336cf55ad371256c9a12a889e98)