runtime(java): Consent to HTML tags folding in Javadoc comments

runtime(java): Consent to HTML tags folding in Javadoc comments

HTML tags in Javadoc comments can additionally be folded
after applying
------------------------------------------------------------
	let g:html_syntax_folding = 1
	set foldmethod=syntax
------------------------------------------------------------

and giving explicit consent with
------------------------------------------------------------
	let g:java_consent_to_html_syntax_folding = 1
------------------------------------------------------------

Do not default to this kind of folding unless ALL start tags
and optional end tags are balanced in Javadoc comments;
otherwise, put up with creating runaway folds that break
syntax highlighting.

resolves: zzzyxwvut/java-vim#8.
closes: #17216

Signed-off-by: Aliaksei Budavei <0x000c70@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>