Add test for rollback trigged by first isTooBig check in withdrawal algorithm

So this is the first of the rollback tests I want to make.

It tests the rollback when the first isTooBig returns true in the withdrawal algorith.

The second test case is in the making.
If I saw this log message alone it'd be hard to guess what it means as there's no context. I think it should at least say this is inside addChange and I'd replace inTot with "input total" and "output total".