Move OSC code to CardinalOSC.{cpp,hpp}

[akx]

A simple refactor of the OSC code from CardinalCommon to separate files for future (soon, if things end up working) extension.

I'm not totally happy with the CARDINAL_OSC_THREAD_FIELD hack – I think it wouldn't be totally bad to have an unused thread handle field, but this works.

Let's see if all the variants build in CI, too 😵‍💫, this works on my machine :)

[dromer]

Hmm, now I'm wondering what you are up to 🤔

[falkTX]

defining class members through macros looks way too messy and ugly, there must be some better way.

[akx]

Pushed a cleaner variant: the thread field is always there (even if possibly unused depending on OSC server threading mode), so the "intrusion" in CardinalCommon.hpp is now just ~3 lines.

[akx]

Hmm, now I'm wondering what you are up to 🤔

Guess I can spill the beans a bit, since I got a prototype working last night: OSC commands to manipulate (list, introspect, add, delete) modules and cables, and an MCP bridge, so an LLM agent can patch a rack 😀

[falkTX]

Well FYI we have no intentions of helping LLMs here.

[akx]

Well FYI we have no intentions of helping LLMs here.

Sure. 👍 That won't touch this repo, but I feel being able to wire the rack over OSC is interesting for other uses too.

[falkTX]

Well FYI we have no intentions of helping LLMs here.

Sure. 👍 That won't touch this repo, but I feel being able to wire the rack over OSC is interesting for other uses too.

Thank you for understanding, and I agree about OSC being interesting on other cases too.
Though the current approach in this PR doesn't seem the way to go for me.