Rename GetTotalRemitted to indicate that it includes all pending and successful remittance, where pending includes freshly submitted remittance as well as retrieable remittance.

The remittance records should be filtered to exclude hard failures - where status=failed and retryAfter is null (transient failures, where status=failed and retryAfter is non-null should be included).

This can be tested via sending a message to kafka for with the results & the results can be viewed via the remittance endpoint. 

An IQE test that can be used to as a foundation for creating tests of this change can be found at https://gitlab.cee.redhat.com/insights-qe/iqe-rhsm-subscriptions-plugin/-/blob/master/iqe_rhsm_subscriptions/tests/swatch-billing/test_remitance.py?ref_type=heads#L108