SaxonCS-HE VS Extension for XSLT 3.0

This is a first stab at providing a Visual Studio extension to use the recently released SaxonCS-HE 13.0 for XSLT 3.0 You can run a stand-alone XSLT 3.0 stylesheet (starting with xsl:template name="xsl:initial-template", you can run a (traditional) XSLT 3.0 transformation against an XML input document and you can run XSLT 3.0 against a JSON input document.