Bug 36105: Add 'No status alias' option

Bug 36105: Add 'No status alias' option

1) Install FreeForm and enable ILLModule, run:
bash <(curl -s https://raw.githubusercontent.com/ammopt/koha-ill-dev/master/start-ill-dev.sh)
2) Visit /cgi-bin/koha/admin/authorised_values.pl add search for 'alias', click on ILL_STATUS_ALIAS
3) Click on the 'New authorized value for ILL_STATUS_ALIAS' button and add 'alias_code' in authorized value and 'Alias Description' in Description
4) Visit /cgi-bin/koha/ill/ill-requests.pl and create a new FreeForm request
5) After created, click 'Manage request', and then click the 'Edit request' button
6) Edit the Status and select 'Alias Description', click 'Submit'
7) Create a second request but do not set a status alias this time
7) Visit /cgi-bin/koha/ill/ill-requests.pl and select 'Alias description' on the 'Status aliases:' left-side filter
8) Notice the correct record is returned.
9) Now repeat 7) and select 'No status alias'. Notice the request with an empty status_alias is returned
10) Repeat 7 but select 'All status aliases'. Notice both requests are returned

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Nell O’Hora <nohora@aub.ac.uk>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>