Currency drop-down list has been added. It retains
the position of selected entry. Clicking on button
toggles between the previously selected currency
and number formats.

Change-Id: I0dea8fc2773497bfaababa418f119d0a5e76cb03
Reviewed-on: https://gerrit.libreoffice.org/22958Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>