Add a test for the total header size limit


Verify that a request whose header fields are each within the per-field
limit but whose combined size exceeds the total header limit is rejected
with 431.

Task-number: QTBUG-150270
Pick-to: 6.12 6.12.0 6.11
Change-Id: I64bab2400bb88905641ed6f6d08be4975609b139
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
commit2813a0d23564c210c863485955fb715eb6bac85f
parentd492b5c58bc534852eaef50e96969de257f33969
authorMate Barany <mate.barany@qt.io>
committerMate Barany <mate.barany@qt.io>
commit timeFri, 25 Sep 2026 07:35:45 +0000