Bug 36396: Export/import the yaml config

Bug 36396: Export/import the yaml config

Test plan:
Export the ES fields/mappings using
 misc/search_tools/export_elasticsearch_mappings.pl > mappings.yaml
Copy this file to admin/searchengine/elasticsearch/mappings.yaml

Reset the mapping from the UI
Notice that the links to the AV categories have been preserved

Sponsored-by: The Research University in the Helmholtz Association (KIT)
Signed-off-by: Lukas Koszyk <lukasz.koszyk@kit.edu>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>