Resolves: tdf#131536 TEXT() support empty format string mimicking Excel

Change-Id: Iffc37179cafb8b8bcfa1232e7aa54ae119ab5846
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/93504
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins
diff --git a/sc/source/core/tool/interpr1.cxx b/sc/source/core/tool/interpr1.cxx
index 839c513..64478375 100644
--- a/sc/source/core/tool/interpr1.cxx
+++ b/sc/source/core/tool/interpr1.cxx
@@ -9562,6 +9562,18 @@ void ScInterpreter::ScText()
        }
        if (nGlobalError != FormulaError::NONE)
            PushError( nGlobalError);
        else if (sFormatString.isEmpty())
        {
            // Mimic the Excel behaviour that
            // * anything numeric returns an empty string
            // * text convertible to numeric returns an empty string
            // * any other text returns that text
            // Conversion was detected above.
            if (bString)
                PushString( aStr);
            else
                PushString( OUString());
        }
        else
        {
            OUString aResult;