tdf#42982 Improved UNO API error reporting.

Messages to thrown `RuntimeException` instances have been added to make
the error clearer.

Change-Id: I566c475bd4ddf891a2cebf15664576cff792c118
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/133100
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
diff --git a/dbaccess/source/core/api/FilteredContainer.cxx b/dbaccess/source/core/api/FilteredContainer.cxx
index 70eb852..a5cf0b1 100644
--- a/dbaccess/source/core/api/FilteredContainer.cxx
+++ b/dbaccess/source/core/api/FilteredContainer.cxx
@@ -132,7 +132,7 @@ static sal_Int32 createWildCardVector(Sequence< OUString >& _rTableFilter, std::
    static void lcl_ensureComposedName( TableInfo& _io_tableInfo, const Reference< XDatabaseMetaData >& _metaData )
    {
        if ( !_metaData.is() )
            throw RuntimeException();
            throw RuntimeException("lcl_ensureComposedName: _metaData cannot be null!");

        if ( !_io_tableInfo.sComposedName )
        {
@@ -153,7 +153,7 @@ static sal_Int32 createWildCardVector(Sequence< OUString >& _rTableFilter, std::
        lcl_ensureComposedName( _io_tableInfo, _metaData );

        if ( !_masterContainer.is() )
            throw RuntimeException();
            throw RuntimeException("lcl_ensureType: _masterContainer cannot be null!");

        OUString sTypeName;
        try