Bug 38961: XSS in vendor search

Bug 38961: XSS in vendor search

acqui/booksellers.tt and admin/currency.tt use | $HtmlTags without first
filtering the string they wrap.

Test plan:
1. Without the patch, load the URL in comment 1, note the alert()
2. Apply patch, load the URL in comment 1, no alert()

Sponsored-by: Chetco Community Public Library
Signed-off-by: Magnus Enger <magnus@libriotech.no>
Followed the test plan, works as advertised.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Alex Buckley <alexbuckley@catalyst.net.nz>
(cherry picked from commit a5afd9c9c8bd3901597a45998bf42b257cf91690)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Jesse Maseto <jesse@bywatersolutions.com>
Signed-off-by: JesseM <jesse@bywatersolutions.com>