Adding more coroutine components to support async generators and task…

… containers (#408)

This PR is related to the Morpheus Sherlock work which uses coroutines. Much of this code was pulled from this branch https://github.com/ryanolson/srf/tree/runnable_next and was in a pretty good state. A few minor tweaks and changes have been added.

Authors:
  - Michael Demoret (https://github.com/mdemoret-nv)

Approvers:
  - Devin Robison (https://github.com/drobison00)
  - Christopher Harris (https://github.com/cwharris)

URL: #408

cpp/mrc/CMakeLists.txt

@@ -115,7 +115,9 @@ add_library(libmrc
   src/public/core/logging.cpp
   src/public/core/thread.cpp
   src/public/coroutines/event.cpp
+  src/public/coroutines/scheduler.cpp
   src/public/coroutines/sync_wait.cpp
+  src/public/coroutines/task_container.cpp
   src/public/coroutines/thread_local_context.cpp
   src/public/coroutines/thread_pool.cpp
   src/public/cuda/device_guard.cpp