[sched] add docker plan class spec

[AenBleidd]

[AenBleidd]

Depends on #5757 that needs to be merged first.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 81 lines in your changes missing coverage. Please review.

Project coverage is 10.48%. Comparing base (27c654f) to head (8c11a98). Report is 177 commits behind head on master.

Files with missing lines	Patch %	Lines
sched/plan_class_spec.cpp	0.00%	72 Missing :warning:
sched/sched_customize.cpp	0.00%	9 Missing :warning:

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5761      +/-   ##
============================================
- Coverage     10.50%   10.48%   -0.03%     
  Complexity     1068     1068              
============================================
  Files           280      280              
  Lines         35972    36053      +81     
  Branches       8448     8481      +33     
============================================
  Hits           3780     3780              
- Misses        31798    31879      +81     
  Partials        394      394              

Files with missing lines	Coverage Δ
sched/plan_class_spec.h	0.00% <ø> (ø)
sched/sched_customize.cpp	0.00% <0.00%> (ø)
sched/plan_class_spec.cpp	0.00% <0.00%> (ø)

[AenBleidd]

@davidpanderson, I have fixed conflicts in this PR. Please review and test when ready. Thank you in advance.

[AenBleidd]

@davidpanderson, I believe this is not relevant anymore. Should I just discard this PR or you still need it for some purposes?

[davidpanderson]

OK to discard.