Bug 33151: Improve translation of string in cities.tt and desks.tt

This patch adds a <span> tag around a string in both cities.tt and
desks.tt in order to improve translatability.

To test apply the patch and run the translation script to update the .po
files, e.g.

perl misc/translator/translate update fr-FR

Check the updated .po files:
 - Before the patch you would have found 'msgid "%s Searching: %s %s %s'
 - After the patch you should find 'msgid "Searching: %s'

Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 2894003792)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>

koha-tmpl/intranet-tmpl/prog/en/modules/admin/cities.tt

@@ -167,7 +167,7 @@
 
     <h1>Cities</h1>
     [% IF city_name_filter %]
-        Searching: [% city_name_filter | html %]
+        <span>Searching: [% city_name_filter | html %]</span>
     [% END %]
 
     [% IF cities_count > 0 %]

koha-tmpl/intranet-tmpl/prog/en/modules/admin/desks.tt

@@ -167,7 +167,7 @@
 
     <h1>Desks</h1>
     [% IF searchfield %]
-        Searching: [% searchfield | html %]
+        <span>Searching: [% searchfield | html %]</span>
     [% END %]
 
     [% IF desks.count %]