Improvements based on customize subcontrols

[James Powell]

See https://forums.ni.com/t5/LabVIEW/Icons-in-XY-graph-scale-legend/m-p/4141418/highlight/true#M1193847

for how to open editor on subcontrol element.

Fix:

• Browse button for Path

‌

[James Powell]

See “Scale legend in Graphs (issue 7).vi” under Development.