tdf#105024 use context to generate "error only" formula string

The ScGlobal::GetErrorString() shortcut produced error constants in the
localized UI language, which was wrong anyway when storing ODFF. Use compiler
with context instead to generate the proper symbols.

However, this currently maps all not defined Err:xxx to #NULL! so to preserve
those additional work is needed.

Change-Id: I1de7621d6349d5b00a5aac1cedc9f265c78c7db1

sc/source/core/data/formulacell.cxx

@@ -1042,7 +1042,10 @@ OUString ScFormulaCell::GetFormula( sc::CompileFormulaContext& rCxt ) const
     OUStringBuffer aBuf;
     if (pCode->GetCodeError() != FormulaError::NONE && !pCode->GetLen())
     {
-        aBuf = OUStringBuffer( ScGlobal::GetErrorString( pCode->GetCodeError()));
+        ScTokenArray aCode;
+        aCode.AddToken( FormulaErrorToken( pCode->GetCodeError()));
+        ScCompiler aComp(rCxt, aPos, aCode);
+        aComp.CreateStringFromTokenArray(aBuf);
         return aBuf.makeStringAndClear();
     }
     else if( cMatrixFlag == MM_REFERENCE )