zero-pad UTM coordinate display in edit form

[caver456]

for example: UTM 10S 0723796E 4376695N shows up that way in the main map top-right coord display, and in the popup if you make a marker, and in the print coordinate list; but the leading zero gets lost in the edit form (10S 723796E 4376695N)

[caver456]

seems silly, but, the user is often used to just quickly pruning the two leftmost digits.