Implement "encoders" for CuMsgs

[gbin]

Now that buffer pools are in, we need to be able to compress them in the logs, more generally we need:

1. A system that allows to plug an "encoder" for specific CuMsgs types
2. A way to set those encoder/decoders in the RON file for a specific task output
3. A way to decode those encoded streams at resim and export stages
4. Their output needs to be bincode and seelmlessly serialized in the CopperList
5. Validate the chain for a video stream taking images, encoding them on a demo stack and a replay stack