Bug 34517: Add option search patron attributes by default

Bug 34517: Add option search patron attributes by default

This patch moves form any staff_searchable attribute being automatically
included in the the Standard patron serch, to allowing the librarian to choose.
Current searchable attributes will be marked as 'searched_by_default'

To test:
1 - Add a searchable patron attribute type
2 - Add some values
3 - Confirm they are searched in a 'Standard' patron search
4 - Apply patch
5 - Go to admin - >patron attribute types
6 - Note new 'Searching' column
7 - Confirm attribute is 'Searched by default'
8 - Confirm searches work as before
9 - Edit the attribute type
10 - Uncheck 'searched_by_default'
11 - Save
12 - Confirm attribute not searched in 'Standard' search
13 - Select the attribute in patron search dropdowns
14 - Confirm it is correctly searched

Signed-off-by: Kelly McElligott <kelly@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>