The jupyter v5.0 protocol specifies that for every request that is handled, a status: idle message will be sent when the request is complete. When receiving this idle message is when callbacks are removed from the table.
I think it makes more sense to prefix with `request` instead of send`. Since
`jupyter-send-execute` seems ambiguous unless you say something like
`jupyter-send-execute-request`. But if you say `jupyter-request-execute` it has
essentially the same meaning as `jupyter-send-execute-request` with the extra
word. It also works better for functions like `jupyter-request-kernel-info` as
opposed to `jupyter-send-kernel-info` which seems to imply that you are sending
the kernel info.
- All messages sent are prefixed like `jupyter-send-*`. So that an
`execute_request` maps to `jupyter-send-execute`.
- All received message handlers are prefixed with `jupyter-handle-*`. So that
an `execute_reply` message would be mapped to `jupyter-handle-execute`. Also
for IOPub messages, the handlers are also prefixed with
`jupyter-handle-<iopub message type>` so that a `stream` message would map to
`jupyter-handle-stream`.
