Use optional dependencies for different MISP integrations

[0snap]

📔 Description

Attributes can either be exported from MISP via ZeroMQ or via Kafka. The MISP plugin supports both, but also used to force the user to have both dependencies installed.

This PR eliminates the need to install both dependencies by using extra dependencies (PEP 508). This breaks how the plugin is installed:

pip install threatbus-misp[zmq]
pip install threatbus-misp[kafka]

A plain pip install threatbus-misp without specifying the extras option works, but the plugin will throw a critical error during config validation and terminate right after.

📝 Checklist

• All user-facing changes have changelog entries.
• The changes are reflected on docs.tenzir.com/threatbus, if necessary.
• The PR description contains instructions for the reviewer, if necessary.

🎯 Review Instructions

Commit-by-commit.

[0snap]

@satta fyi 😉 that should simplify the dependency management!

[satta]

That sounds great! 👍

[lava]

I don't have a lot of context to be able to comment on the contents, but the code looks reasonable.

[satta]

Looks good, will test once we upgrade to the latest version everywhere. Not sure how I would test this [] syntax without it being on PyPi.

[0snap]

@satta you can simply do pip install .[zmq]
or from git root: pip install plugins/apps/threatbus_misp[zmq]

[satta]

Ah thanks! I tried pip install git+https://... but wasn't sure how to pass the feature options there.