Make transformer Reset button not grade the item

Summary:
The reset button's default type of "submit" was causing the
answerform to submit and the problem to be graded when it was
pressed. This meant that if the answer was the same as the starting
position, pressing reset would grade the problem as correct

Test Plan:
make a transformer with the answer being no transformations, and no
separate answer input (answer type = custom format)
preview the item
move the polygon
press reset
verify that the item has not been marked correct
press check answer
verify that the item is now marked correct with three leaves

Auditors: alex