Adds a pw::work_queue::WorkQueue concept which is comprised of a
queue of pw::Functions and a singular thread which drains the
queue.
Change-Id: I67d595c097222f8c3a582c990434abeadbb8910a
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/56269
Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Keir Mierle <keir@google.com>