Update guide with new DTD and Catalog properties

JDK 22 adds two new properties `jdk.xml.dtd.support` and `jdk.xml.jdkcatalog.resolve`, and a built-in catalog. The DTD property is used for controlling how DTDs are processed, while the built-in Catalog handling external references. It would be good if we could update the guide with these two properties and the built-in catalog.

jdk.xml.dtd.support: refer to the definition in the table "Implementation Specific Properties" (https://download.java.net/java/early_access/jdk22/docs/api/java.xml/module-summary.html#Properties), and note 7.

With this property, we can update the "DTD Properties" section in the guide to encourage using the new property instead of the two older properties:
    -- create a new section that describes the new DTD property (jdk.xml.dtd.support) as the mechanism on controlling DTD processing;
    -- keep the two existing DTD-related properties as being continually used for compatibility.


jdk.xml.jdkcatalog.resolve, and the built-in Catalog: in the "Using Resolvers and Catalogs" section, we currently have two sub-sections: "Java XML Resolvers" and "the Catalog API", we may add a new sub-section "The built-in Catalog" with content similar to that of the same section in the java.xml module-summary (it's not in the JDK 22 early access javadocs yet, but I'll provide an internal build in the comment section).

See also JDK-8306632 and JDK-8306055