RFR(JDK 14/java.xml) 8223291: Whitespace is added to CDATA tags when using OutputKeys.INDENT to format XML

[Joe Wang]

Please review a fix to xml pretty print. This is a regression introduced 
during the JDK 9 development. CDATA is marked up to be interpreted 
literally as textual data, in other words, it's still character data. 
The processor therefore shall treat it as text data. The content of 
"abc<![CDATA[ & ]]>xyz" should be "abc & xyz", not "    abc\n & \n    
xyz\n" as that before this fix.

JBS: https://bugs.openjdk.java.net/browse/JDK-8223291
webrev: http://cr.openjdk.java.net/~joehw/jdk14/8223291/webrev/
Thanks,
Joe