Harden frame processing on large data

[uranusjr]

Previously, frame encoding and decoding are done against an in-memory byte array. This is simple, but may cause issues with very large amount of data, since the frame protocol allows 2^32 bytes of data per frame with the potential to clog the entire JVM.

This uses the MessagePack library's MessageBuffer helper to encode to and decode from a MessagePack message into multiple lazy buffers, converting each buffer to a byte array separately on demand to reduce peak memory usage.

I also cleaned up some abstractions since they are already pretty empty prior to this change.

[phanikumv]

Suggested change

	try {
	Frame.decode(ChannelFrameInput(reader, declaredLength))
	} catch (e: Exception) {
	logger.error(
	"Failed to read or decode frame",
	mapOf("length" to declaredLength, "exception" to e),
	)
	shutDownRequested = true
	return
	}
	try {
	Frame.decode(ChannelFrameInput(reader, declaredLength))
	} catch (e: CancellationException) {
	throw e
	} catch (e: Exception) {
	logger.error(
	"Failed to read or decode frame",
	mapOf("length" to declaredLength, "exception" to e),
	)
	shutDownRequested = true
	return
	}

[phanikumv]

(needs import kotlinx.coroutines.CancellationException)

catch (e: Exception) also catches CancellationException, so a cancellation during decode becomes a clean shutdown instead of propagating. Minor and
pre-existing in this file, but the new broad catch makes it worth rethrowing.