Shared Kit: Introduce BMemoryRingIO, a thread-safe ring buffer

This commit introduces a simple thread-safe ring buffer implementation
based on top of BDataIO. The main use case for this class will be to
implement shared buffers between threads for the upcoming refactoring
of Services Kit.

Change-Id: I526bc044b28c91496ad996fabebe538e75647f2c
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2966
Reviewed-by: Jacob Secunda <secundaja@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>