In number formatter dialog:

Some locales may define duplicated formats, specifically date
formats, for all builtin formats <50 must be present and default
formats may be equal to other formats. Try to suppress duplicated
formats, preferring those that are essential (i.e. used as
current, default or edit formats). This is done only per category,
not in the All category.

Example is [en-ZA] English (South Africa) that now has ISO 8601
also as default date+time format, though there only the date+time
format is suppressed because for date we want to keep both the
locale's default and the fixed ISO format pickable.

The All category still listed the since long deprecated old
currency formats including the worrying CCC format that follows
the current default currency. Eliminate that crap, unless one
matches the current format.

Also, additional formats defined in locale data and user defined
formats were never listed in the All category, do that.

Change-Id: I6e6b9bfecc34d51e89930f348f7afbe5e3c41738
Reviewed-on: https://gerrit.libreoffice.org/61275Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>