Remove empty callbacks

[Juliaj]

Follow up of #1477 (review). This is to remove empty callback, e.g. on_cleanup, on_deactivate from code base.

A noob question, based on node life_cycle doc , there are predefined roles for these call backs. Why were these coded as empty ? Was it for readability or a place holder for further development ?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.87%. Comparing base (e0b929b) to head (f4d6b25).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1488      +/-   ##
==========================================
+ Coverage   83.86%   83.87%   +0.01%     
==========================================
  Files         122      122              
  Lines       11148    11140       -8     
  Branches      948      946       -2     
==========================================
- Hits         9349     9344       -5     
+ Misses       1486     1485       -1     
+ Partials      313      311       -2     

Flag	Coverage Δ
unittests	83.87% <ø> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...dmittance_controller/src/admittance_controller.cpp	74.71% <ø> (+0.55%)	⬆️
...jectory_controller/joint_trajectory_controller.hpp	100.00% <ø> (ø)
...ory_controller/src/joint_trajectory_controller.cpp	83.88% <ø> (-0.05%)	⬇️
pid_controller/src/pid_controller.cpp	68.42% <ø> (-0.28%)	⬇️

... and 4 files with indirect coverage changes

[christophfroehlich]

A noob question, based on node life_cycle doc , there are predefined roles for these call backs. Why were these coded as empty ? Was it for readability or a place holder for further development ?

These are virtual methods defined in the LifecycleNodeInterface, and don't need to be overridden if there is no action to be done at the respective transition. Why they are here? I guess just because of copying a template around.

[christophfroehlich]

Thanks for the cleanup.

[saikishor]

LGTM