Add support for 'dohpath' to SVCB (and HTTPS) [v9_18]
dohpath is specfied in draft-ietf-add-svcb-dns and has a value of 7. It must be a relative path (start with a /), be encoded as UTF8 and contain the variable dns ({?dns}).
(cherry picked from commit 6d561d38)
Closes #3544 (closed)
Edited by Mark Andrews