Improve error handling and logging in CommsDecoder interface

[ashb]

Resurrect #45927 and extend it.

Every request should have a response that the client reads.

We need the ability to pass/send errors from Supervisor to the task code (for instance if there is an error performing an action, or if the XCom can't be found) -- right now each end point handles this itself in a different way.

airflow/task_sdk/src/airflow/sdk/api/client.py

Lines 267 to 282 in eb05869

	except ServerResponseError as e:
	if e.response.status_code == HTTPStatus.NOT_FOUND:
	log.error(
	"XCom not found",
	dag_id=dag_id,
	run_id=run_id,
	task_id=task_id,
	key=key,
	map_index=map_index,
	detail=e.detail,
	status_code=e.response.status_code,
	)
	# Airflow 2.x just ignores the absence of an XCom and moves on with a return value of None
	# Hence returning with key as `key` and value as `None`, so that the message is sent back to task runner
	# and the default value of None in xcom_pull is used.
	return XComResponse(key=key, value=None)

for example shouldn't be handled in the API Client, but it should expose/raise the 404 to the Task itself and it should be handled there