Add support for parsing the EE 9 connector_2_0.xsd

The EE 9 connector_2_0.xsd should be semantically equivalent to the EE 7/8 connector_1_7.xsd, except a different value in the document's 'version' attribute.

https://jakarta.ee/xml/ns/jakartaee/connector_2_0.xsd

IJ should add support for parsing such documents.

This isn't about any EE 9 Java APIs, the jakarta.* package namespace etc. It's just about the existing IJ recognizing an EE 9 document and treating it like it treats a EE 7/8 document.