[PATCH] http: return error when receiving too large header set

[PATCH] http: return error when receiving too large header set

To avoid abuse. The limit is set to 300 KB for the accumulated size of
all received HTTP headers for a single response. Incomplete research
suggests that Chrome uses a 256-300 KB limit, while Firefox allows up to
1MB.

Closes #11582

Backport to Debian by Carlos Henrique Lima Melara <charlesmelara@riseup.net>

Gbp-Pq: Name CVE-2023-38039.patch