EM-1256 Send notification with results of ACH query

[e-manifest]

Send an email to payer of a bill when the ACH Query process determines that the payment has been processed (either successfully or not).

Acceptance Criteria
(x) When a site's ACH transaction submission is determined to be successful, the payer receives an email notification that their payment has been successfully processed.
(x) When a site's ACH transaction submission has a transaction failure reported, the payer receives an email notification that their payment has not been successful and further action is required to pay their bill.
(x) When a hard error is returned, send a message to the user.
(x) When the 7 day check is expired, also send a message to the user.