Bug 26991: Add action logs to search engine administration

Bug 26991: Add action logs to search engine administration

Search engine administration is very important,
we should log who/when it is changed.
I don't add a preference system to disable it,
like there is no for preference system logs.

Test plan :
1) Use searchengine Elasticsearch
2) Go to Administation > Search engine configuration (Elasticsearch)
3) Click on 'Reset Mappings' and accept
4) Edit some lines and save
5) Go to 'Tools' > 'Log viewer'
6) Select only 'Search engine' in Modules and submit
7) Select only 'Edit mappings' in Actions
8) Check you see a log
9) Select only 'Reset mappings' in Actions
10) Check you see a log

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>