Missing version in stylesheet

Every xsl:stylesheet should declare an id attribute with a unique value. Without it, stylesheets are indistinguishable in logs, error messages, and tooling that processes multiple stylesheets together.

Incorrect:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <!-- stylesheet logic -->
</xsl:stylesheet>

Correct:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" id="stylesheet_name">
    <!-- stylesheet logic -->
</xsl:stylesheet>