Add a condition to the merge mail to only send out the message to tenants that actually have an outstanding bond, instead of sending it out with a "$0.00" amount

Add another merge field for the bond top-up, so only the bond amount that is outstanding on today's date will be sent to the tenant, and it doesn't add the bond amount of the next rent increase as well. Need a merge field for "outstanding bond up until today" and one for "outstanding bond in total".