Errors in callbacks when running async is not calling _on_error()

If a `Notifier` is created using an asyncio loop, any errors that occurs in the receive callbacks will not call the `Listener._on_error()` callback. It does when not running asyncio.

Looking at `Notifier._rx_thread()`: When a loop is present it will call `Notifier._on_message_received()` using the `self._loop.call_soon_threadsafe()` call. However the `except Exception as exc:` in line 127 will never be reached, because any errors in the `call_soon_threadsafe()` callback does not return the exceptions for the function it calls. This in turn implies that when asyncio is enabled, the `Listener._on_error()` callback won't be called either which is unexpected.

https://github.com/hardbyte/python-can/blob/654a02ae24bfc50bf1bb1fad7aab4aa88763d302/can/notifier.py#L111-L137

The fix would be to either encapsulate `Notifier._on_message_received()` in an except block and call the `_on_error()` call back from it. Another solution is to make it call an extra handler when running async:

```py
def _rx_thread(self, bus: BusABC) -> None:
# determine message handling callable early, not inside while loop
if self._loop:
def rx_handler(msg: Message) -> None:
try:
self._on_message_received(msg)
except Exception as exc:
if not self._on_error(exc):
raise
else:
# It was handled, so only log it
logger.debug("suppressed exception: %s", exc)
handle_message: Callable[[Message], Any] = functools.partial(
self._loop.call_soon_threadsafe,
rx_handler, # type: ignore[arg-type]
)
else:
handle_message = self._on_message_received
...
```

Probably related to #1865