Debit/Deposit behavior is inconsistent with rendered dashboard balance

[MitchellDill]

Currently, when clicking between the deposit/debit buttons on the add transaction page result in unpredictable behavior with the amount being deposited/debited. The amount to be deposited gains, or sometimes loses a negative sign when toggling them, but not consistently. We should ensure behavior is consistent and also that the user knows what a negative sign means, if that's going to appear.

Also, the net balance on the dashboard appears to read deposits as debits. So we should make sure that's working as intended!