Allow panning while Measure Tool selected

[jidanni]

It seems each time we need to move the screen while in Measure Tool mode,
we must quit out of the Measure Tool, go into pan mode,
and then reselect the Measure Tool.

So panning should still be allowed via the usual mouse dragging.

Upon further investigation, it seems one could measure just fine already,
without needing to hijack "hold down and move the mouse" to the Measure Tool,
when it could continue to do its pan job just fine. Viking 1.10.

[rnorris]

There is a permanent pan mode available (regardless of the tool/mode selected) using the middle mouse button (hold down and move mouse around) - hence you don't need to switch between any tool and pan mode.

However it will remove the Ruler drawing overlay when you pan.
Since internally the Ruler positioning is held in a place that isn't accessible to the pan drawing.
Thus for that to happen it would require some amount of rework to the internals :(

[jidanni]

Kind of challenging on a Chromebook with only a trackpad...
Yes I'm sure there is a finger combination to do it, but it
might require lots of dexterity.