run_once fixes

[wtgee]

Fix for the run_once parameter so that it can be specified at Object or method level properly. Fixes #236

[codecov]

Codecov Report

Merging #509 into develop will decrease coverage by 0.03%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop     #509      +/-   ##
===========================================
- Coverage    70.48%   70.45%   -0.04%     
===========================================
  Files           62       62              
  Lines         5418     5418              
  Branches       751      751              
===========================================
- Hits          3819     3817       -2     
- Misses        1392     1393       +1     
- Partials       207      208       +1

Impacted Files	Coverage Δ
pocs/state/machine.py	88.96% <100%> (ø)	⬆️
pocs/serial_handlers/protocol_arduinosimulator.py	76.92% <0%> (-0.39%)	⬇️
pocs/observatory.py	81.59% <0%> (-0.28%)	⬇️

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