Bug 31271: Preselect previous search index

Bug 31271: Preselect previous search index

This patch passes the constructed value of the preselect to search_indexes.inc

To test:
1 - Perform an advanced search, making sure to select different indexes
2 - Click 'Edit search' on results page
3 - Confirm index selections are preselected
4 - Enable  IntranetCatalogSearchPulldown
5 - Do a search form the top bar using an index
6 - Confirm 'Edit search' correctly popluates the chosen index

Signed-off-by: Andrew Fuerste-Henry <andrewfh@dubcolib.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>