Bug 10381: Followup adding some text around Apply/cancel filter.

Bug 10381: Followup adding some text around Apply/cancel filter.

The texts Apply/cancel filter did not need translation and were used to get
this change into 3.12.
For 3.12.X or 3.14 we can add some words to clarify its meaning.
With thanks to Owen for some rewording.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Pierre Angot <tredok.pierre@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>