[Asterisk] Package `pyst2` stopped being maintained

[amotl]

Problem

• The most recent release of https://pypi.org/project/pyst2/ was in 2019.
• The repository at https://github.com/rdegges/pyst2 has been archived.

Research

There are updates from the community with recent commits at https://github.com/rdegges/pyst2/network.

• https://github.com/epoch8/pyst3
• https://github.com/chrishem/pyst3
• https://github.com/invitecomm/pyst2/tree/develop

There is also another library, py-Asterisk.

Question to the community

Does anybody know which would be the best library to use these days? For modernizing mqttwarn on this matter, the goal would be to have the package available on PyPI.

/cc @rdegges, @epoch8, @chrishem, @invitecomm