We've seen errors caused by what we suspect is a race condition when
SES callback processing tries to look up the notification before the
sender worker has saved notification reference from the SES POST
response to the database.
This adds a retry for SES callback task if the notification was not
found and the message is less than 10 minutes old and removes the
error log message for notifications older than 3 days (since they
might no longer exist in the notifications table and would've been
marked as failure by then either way).
In order to be able to call retry and silence the error log based on
notification time this change inlines `process_ses_response` and
`update_notification_by_reference` functions into the celery task.
It also removes a lot of defensive error-handling that doesn't appear
to have been triggered in the last few months (for things like missing
keys in SES callback data).
The json we were getting from SES was not quite as expected, the test data now reflects what we get.
New test added, fix a test that was passing regardless.
When handling the complaint we don't want to throw an exception if the message is missing fields. Only log an exception if we are unable to tie a complaint to a notification.
