stats: some circulation stats are incorrect because they also count notifications

[PascalRepond]

Bug description:

Billing and librarian stats that use the OperationLogs index now sometimes also count operation logs of type "notif" when they shouldn't.

For example:

        return RecordsSearch(index=LoanOperationLog.index_name)\
            .filter('range', date=self.date_range)\
            .filter('term', loan__trigger=trigger)\
            .filter('term', loan__item__library_pid=library_pid)\
            .count()

This filter OperationLogs by loan.trigger to count circulation actions but since the loan data is now dumped into the notification operation log, they are also counted.

We need to find all of these RecordsSearch(index=LoanOperationLog and check that they count what they are supposed to count. Most likely add a filter type="loan" when we want to count circulation operations and not notifs.

Expected behavior:

Notifications operation logs are not wrongfully counted when generating stats .

Context

Server:

• production: bib.rero.ch or ils.bib.uclouvain.be

Version:

v1.18.0