Bug 32057: Add optional stack trace to action logs

Bug 32057: Add optional stack trace to action logs

It can be useful to know where in Koha a particular logged action was generated from, and how. We should add the ability to attach a syspref controlled basic stack trace with the caller depth controlled via the syspref. We can the call caller() until the specified depth has been reached.

Test Plan:
1) Apply this patch
2) Run updatedatabase.pl
4) Restart all the things!
5) Set the new syspref ActionLogsTraceDepth to a number ( e.g. 3 )
6) Update a syspref or trigger another enabled log action
7) Query the database: SELECT * FROM action_logs WHERE trace IS NOT NULL
8) Note the stack trace was created!

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>