DoH: improvements

DoH: improvements

- decode results when individual requests are done
- makes happy eyeballing start asap
- remove doh_resp structures as no longer needed
- remove CURL_DNS_TYPE_NS, CURL_DNS_TYPE_CNAME and
  CURL_DNS_TYPE_DNAME from DoH
- DoH: do not set PIPEWAIT and SSL OPTS when url starts with http:
- mark Doh master handle as dirty after every sub-request, not only the last
- Doh: start probe on AAAA before A (was the other way).

cf-dns: set EXPIRE_HAPPY_EYEBALLS timer when waiting 50ms on AAAA
result or progress will not be triggered in time.

Add debug env var CURL_DBG_HE_AAAA_AWAIT_MS to override the
default 50ms on waiting for the AAAA result to arrive.

test2100: set CURL_DBG_HE_AAAA_AWAIT_MS to 60 seconds to
provide enough time for slow CI runs to sent all DoH requests.

closes #22514