"Thousands Separator" and "Engineering notation" used the same checkbox,
so help tips texts were the same.
This commit creates a second checkbox
which is hiden/shown according to category selected
Change-Id: I94913e63e47b760deb747ce7cd3d74ab4c109599
Reviewed-on: https://gerrit.libreoffice.org/24224
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>