[DISCUSS] Enables pulsar to configure the `MaxRequestHeaderSize` of the internal web service

[Yubiao Feng <yu...@streamnative.io.INVALID>]

Hi community

The Client API can create topic names of infinite length. But after these
topics were created, we can not manage them by Admin API because the web
service (based by Jetty) has a request-line length limit.

I propose adding a pulsar configuration `httpMaxRequestHeaderSize` to set
this internal web service config (including web servicer and proxy service).

I have submitted a PR to do this:
https://github.com/apache/pulsar/pull/19514

Due to the previous bug of loop creation of DLQ(see
https://lists.apache.org/thread/q1m23ckyy10wvtzy65v8bwqwnh7r0gc8), I think
customers should need this configuration to remove these topics that
shouldn't exist, so I think this change should be cherry-picked into
branches 2.9, 2.10, and 2.11


Thanks
Yubiao Feng