Bug 36282: Chomp whitespace around opac i18n strings

Bug 36282: Chomp whitespace around opac i18n strings

Same logic as bug 26816 but to OPAC

Test plan:
1) Apply test plan patch only
2) Visit opac home:
<opac_url>/cgi-bin/koha/opac-main.pl
3) Notice there's a space between 'Translated string' and ':', even though the markup does not contain a whitespace
4) Apply 2nd patch
5) Notice the white space is gone

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit b9f97ec015e4f101546e308754db4ed532987fde)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>