Combine like code into one common place with the task plugin.

src/plugins/task/affinity/affinity.c

src/plugins/task/affinity/affinity.h

src/plugins/task/affinity/dist_tasks.c

src/plugins/task/affinity/schedutils.c

src/plugins/task/affinity/task_affinity.c

src/plugins/task/cgroup/task_cgroup_cpuset.c

src/slurmd/common/task_plugin.c

src/slurmd/common/task_plugin.h