runtime(htmldjango): Add syntax highlighting of comparison operators

runtime(htmldjango): Add syntax highlighting of comparison operators

The presence `djangoOperators` in the file `syntax/django.vim` and
having the highlight function with a `match` statement leads to a
highlight spill-over with other elements defined in `syntax/html.vim`.
To avoid the highlight spill-over declare a region called
`djangoTagBlockNaive` to limit `djangoOperator` to only be matched
within.

related: #20225
closes:  #20232

Signed-off-by: tecis <67809811+tecis@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>