Update zmq notification documentation and sample consumer

Summary:
This is a backport of core#19572 [4/4]
https://github.com/bitcoin/bitcoin/pull/19572/commits/759d94e70f6844443106404882c7b105f3a4dba7

Depends on D10306

I had to revert the IP address change from D1120 to make the zmq_sub.py script work.

Test Plan:

$ src/bitcoind  -daemon -zmqpubrawtx=tcp://127.0.0.1:28332 -zmqpubrawblock=tcp://127.0.0.1:28332 -zmqpubhashtx=tcp://127.0.0.1:28332  -zmqpubhashblock=tcp://127.0.0.1:28332  -zmqpubsequence=tcp://127.0.0.1:28332
$ python ../contrib/zmq/zmq_sub.py

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D10307