Since eventually we want to implement all other RPC "func types" as
contexts underneath this starts the rework to move all the other cases
into a separate func not only to simplify the main `._invoke()` body but
also as a reminder of the intention to do it XD
Details of re-factor:
- add a new `._invoke_non_context()` which just moves all the old blocks
for non-context handling to a single def.
- factor what was basically just the `finally:` block handler (doing all
the task bookkeeping) into a new `@acm`: `_errors_relayed_via_ipc()`
with that content packed into the post-`yield` (also with a `hide_tb:
bool` flag added of course).
* include a `debug_kbis: bool` for when needed.
- since the `@context` block is the only type left in the main
`_invoke()` body, de-dent it so it's more grok-able B)
Obviously this patch also includes a few improvements regarding
context-cancellation-semantics (for the `context` RPC case) on the
callee side in order to match previous changes to the `Context` api:
- always setting any ctxc as the `Context._local_error`.
- using the new convenience `.maybe_raise()` topically (for now).
- avoiding any previous reliance on `Context.cancelled_caught` for
anything public of meaning.
Further included is more logging content updates:
- being pedantic in `.cancel()` msgs about whether termination is caused
by error or ctxc.
- optional `._invoke()` traceback hiding via a `hide_tb: bool`.
- simpler log headers throughout instead leveraging new `.__repr__()` on
primitives.
- buncha `<= <actor-uid>` sent some message emissions.
- simplified handshake statuses reporting.
Other subsys api changes we need to match:
- change to `Channel.transport`.
- avoiding any `local_nursery: ActorNursery` waiting when the
`._implicit_runtime_started` is set.
And yes, lotsa more comments for #TODOs dawg.. since there's always
somethin!