Add capability to fetch coroutine stack trace in one call

[nikita-nazarov]

Depends on: https://github.com/JetBrains/kotlin/pull/5088

This commit adds a wrapper over the new compiler API that allows fetching a coroutine stack trace in one call, which will significantly speed up async stack trace fetching when debugging an android app on a phone. Also a couple of minor improvements of the coroutine debugger are added.