Functional Safety Editor: Add pan tool to diagram

[MichaelBalzer]

The Functional Safety Editor lacks a pan tool for navigating the diagram view. The only option is to use the scrollbars + mousewheel.

This proposal is to add a pan tool, activated by a keyboard+mouse shortcut. This could be Ctrl+Shift+Click (like LabVIEW) or Space+Click (like NXG). This would make navigating the diagrams of larger safety programs much quicker.