XRENDERING-324: ConfluenceXHTMLParser does not repair CDATA containing square brackets

 * "repair" the CDATA sections the moment they come put of the entities.xml
 * add testcase - disabled yet as this needs one more fix with the attachments

(cherry picked from commit 2ef01a9e102e15c5f318c1ab88ff399fa36f30fe)
XWIKI-9803 (was XRENDERING-324): confluence CDATA repair stuff

 * use precompiled pattern for repair
 * rename test data to updated issue name

(cherry picked from commit 05212f2548239ce985086fb0a0c2ce52f5f18f08)