Adding a support for codec server

[dimostenis]

Is your feature request related to a problem? Please describe

We're building a platform on top of Zigflow and we truly NEED to use our custom codec server.

Describe the behaviour you'd like

Add a new CLI flag for passing a codec. Like --convert-data --codec-endpoint http://localhost:8081.

Describe alternatives you've considered

Not using Zigflow. Building our own declarative workflow worker. Not preferred:)

Additional context

We already built it into Zigflow as a POC. I am ready to post a PR. Including an example (by adding into ./examples) of how the codec, written in python, offloads payloads larger than 10KB to external storage (actually /tmp 🙃).

Its about 60 lines in root.go and new pkg/codec/remote.go (200 lines) for calling /encode, /decode.

We believe custom codec support is a crucial missing functionality.

[mrsimonemms]

Funny you should mention this, I was only thinking about this earlier today.

Strictly speaking, we don't encourage external data converters, but I think that this is a good use case. I'd love to see your solution.

[dimostenis]

Great to hear you're open to it! Here it goes: #250