Related: tdf#119613 tdf#118127 suppress duplicated builtins, rework All cat

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>

include/svx/numfmtsh.hxx

@@ -197,15 +197,20 @@ private:
     bool                    bIsDefaultValNum;
 
     SVX_DLLPRIVATE short FillEntryList_Impl( std::vector<OUString>& rList );
-    SVX_DLLPRIVATE void  FillEListWithStd_Impl( std::vector<OUString>& rList,sal_uInt16 aPrivCat, short &Pos);
+    SVX_DLLPRIVATE void  FillEListWithStd_Impl( std::vector<OUString>& rList, SvNumFormatType eCategory, short &Pos,
+                                                bool bSuppressDuplicates = false );
     SVX_DLLPRIVATE short FillEListWithFormats_Impl( std::vector<OUString>& rList,short nSelPos,
                                                        NfIndexTableOffset eOffsetStart,
-                                                       NfIndexTableOffset eOffsetEnd);
-    SVX_DLLPRIVATE short FillEListWithDateTime_Impl( std::vector<OUString>& rList,short nSelPos);
+                                                       NfIndexTableOffset eOffsetEnd,
+                                                       bool bSuppressDuplicates );
+    SVX_DLLPRIVATE short FillEListWithDateTime_Impl( std::vector<OUString>& rList,short nSelPos,
+                                                     bool bSuppressDuplicates );
     SVX_DLLPRIVATE short FillEListWithCurrency_Impl( std::vector<OUString>& rList,short nSelPos);
     SVX_DLLPRIVATE short FillEListWithSysCurrencys( std::vector<OUString>& rList,short nSelPos);
     SVX_DLLPRIVATE short FillEListWithUserCurrencys( std::vector<OUString>& rList,short nSelPos);
-    SVX_DLLPRIVATE short FillEListWithUsD_Impl( std::vector<OUString>& rList, sal_uInt16 nPrivCat, short Pos );
+    SVX_DLLPRIVATE short FillEListWithUsD_Impl( std::vector<OUString>& rList, SvNumFormatType eCategory, short Pos );
+
+    SVX_DLLPRIVATE bool IsEssentialFormat_Impl( SvNumFormatType eType, sal_uInt32 nKey );
 
     SVX_DLLPRIVATE ::std::vector<sal_uInt32>::iterator GetRemoved_Impl( size_t nKey );
     SVX_DLLPRIVATE bool                                IsRemoved_Impl( size_t nKey );