Investigate possible shortcuts for coroutineContext.job.invokeOnCompletion { if (it != null) ... }

[qwwdfsad]

The pattern itself is useful for any closeable resources that face non-atomic cancellation (#1191) as the only reliable way to close it.

Apart from that, the pattern itself is very clunky, but seems to be quite frequent: [1], [2].

We should investigate whether we can provide more convenient extensions on top of CoroutineContext and CoroutineScope