Adding source file and linenumber in Warn and Info xml tags

[vvvlc]

Description

Hi
I would like to have file name and line number attributes in Warn and Info tags of xml reporter, so I can easily identify find them in source code. Moreover this would be more consistent with Failure or Expression that already exposes such information.

Steps to reproduce

TEST_CASE("simple test"){
	INFO("tmp start----------------");
	WARN("go  end----------------");
}

Generates

      <Warning>
        go  end----------------
      </Warning>
      <Info>
        tmp start----------------
      </Info>

I would like to add additional attributes like filename and line.

      <Warning filename="../src/tests.cc" line="62">
        go  end----------------
      </Warning>
      <Info filename="../src/tests.cc" line="58">
        tmp start----------------
      </Info>

Extra information

Here proposal for improvement of bool XmlReporter::assertionEnded( AssertionStats const& assertionStats ), adding writeSourceInfo( msg.lineInfo )

            for( auto const& msg : assertionStats.infoMessages ) {
                if( msg.type == ResultWas::Info && includeResults ) {
                    auto tag = m_xml.scopedElement( "Info" );
                    writeSourceInfo( msg.lineInfo );
                    tag.writeText( msg.message );
                } else if ( msg.type == ResultWas::Warning ) {
                    auto tag = m_xml.scopedElement( "Warning" );
                    writeSourceInfo( msg.lineInfo );
                    tag.writeText( msg.message );
                }

Thx
Vitek