BUG/MINOR: h3: reject invalid :path in request

BUG/MINOR: h3: reject invalid :path in request

RFC 9114 specifies some requirements for :path pseudo-header when using
http or https scheme. This commit enforces this by rejecting a request
if needed. Thus, path cannot be empty, and it must either start with a
'/' character or contains only '*'.

This must be backported up to 2.6.

(cherry picked from commit fc28fe7191701251115e817a7c4a673b88e49f65)
Signed-off-by: Aurelien DARRAGON <adarragon@haproxy.com>
(cherry picked from commit cb5ff8cf01212b321b15f24a3f28b68154774955)
Signed-off-by: Aurelien DARRAGON <adarragon@haproxy.com>