Add integration with Kotlin IO multiplatform library

[sandwwraith]

This will address:
#66, #204 and #251.

kotlinx.io.core.Input/Output should replace ByteArrays and Strings in Binary and String formats, thus allowing to work with streaming API and easily convert content to either byte arrays or strings with desired charsets.

[StephenOTT]

Any timeline on this? 2019? End of 2020?

[sandwwraith]

@StephenOTT As soon as kotlinx-io is ready (currently it is under huge refactoring).

[StephenOTT]

Great. Thanks.

[DaanVandenBosch]

It seems like not much is happening on the kotlinx-io repository. Is the plan still to support the use-cases linked to by this issue (e.g. (de)serializing to/from bytes) via kotlinx-io?

[sandwwraith]

Unfortunately, kotlinx-io project is indeed postponed at the time of writing. We still have a plan to provide API to interact with Java's Input/OutputStreams in 1.2 release