Add skipManyInterleavedTill combinator

[alanz]

At the moment I have the completion tests in my local environment failing for hie, due to

_ <- skipManyTill loggingNotification (count 2 noDiagnostics)

which in my case receives a diagnostics notification, then a logging notification, then the second diagnostic.

What I actually want to say is skip any logging notifications until we have received two diagnostics notifications.

Is this currently possible? If not, we should make it so.

[alanz]

I guess it can be emulated by

    _ <- count 2 $ skipManyTill loggingNotification (count 1 noDiagnostics)

so perhaps does not need to be anything special. But it does come up in a lot of tests.

[lukel97]

I think that can be shortened to

_ <- count 2 $ skipManyTill loggingNotification noDiagnostics

But at this point I think it is worthwhile just looking into a config option to just ignore all logging notifications, for practicality's sake

[lukel97]

Closed in cb75f57