* When an account is deleted, subplat data associated with the user (including nimbus-associated data) needs to be removed as well
This commit:
* Adds in a record-keeping deletionNamespaces field to the nimbus config, for ensuring deletion of data associated with historical nimbus UUID generations
* Logs a record via the winston logger in a format designed to be intercepted by a bigquery ETL query to delete glean data with a matching nimbus user id
* Wires in the deletion logger method into the fxa webhook call for the delete-user fxa events
Closes #PAY-3438