Highlighting in documents doesn't handle CDATA sections correctly

[jan-niestadt]

"Tags" inside a CDATA are seen as actual (unbalanced) XML open tags, and closing tags are added at the end of the document.

Example:

https://portal.clarin.ivdnt.org/blacklab-server-new/opensonar/docs/WR-P-E-C-0000000129/contents?query=%5Bword%3D%22schip%22%5D&wordstart=7000