Namely renaming and tweaking the `MsgType` receiving methods,
- `.recv_msg()` from what was `.recv_msg_w_pld()` which both receives
the IPC msg from the underlying `._rx_chan` and then decodes its
payload with `.decode_pld()`; it now also log reports on the different
"stage of SC dialog protocol" msg types via a `match/case`.
- a new `.recv_msg_nowait()` sync equivalent of ^ (*was*
`.recv_pld_nowait()`) who's use was the source of a recently
discovered bug where any final `Return.pld` is being
consumed-n-discarded by by `MsgStream.aclose()` depending on
ctx/stream teardown race conditions..
Also,
- remove all the "instance persistent" ipc-ctx attrs, specifically the
optional `_ipc`, `_ctx` and the `.wraps_ipc()` cm, since none of them
were ever really needed/used; all methods which require
a `Context/MsgStream` are explicitly always passed.
- update a buncha typing namely to use the more generic-styled
`PayloadT` over `Any` and obviously `MsgType[PayloadT]`.
1ce99ae742