[CM] Improve memory allocation with buffer variables

[saikishor]

This PR tries to address the issue of memory allocation in the RT loop of the CM read, write, and update cycles

[codecov]

Codecov Report

Attention: Patch coverage is 97.05882% with 1 line in your changes missing coverage. Please review.

Please upload report for BASE (master@4eabd25). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
.../include/controller_manager/controller_manager.hpp	91.66%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #1801   +/-   ##
=========================================
  Coverage          ?   87.26%           
=========================================
  Files             ?      121           
  Lines             ?    12091           
  Branches          ?     1077           
=========================================
  Hits              ?    10551           
  Misses            ?     1149           
  Partials          ?      391           

Flag	Coverage Δ
unittests	87.26% <97.05%> (?)

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Files with missing lines	Coverage Δ
controller_manager/src/controller_manager.cpp	76.99% <100.00%> (ø)
.../include/controller_manager/controller_manager.hpp	96.66% <91.66%> (ø)

[fmauch]

This seems fair. Is there a reason that you went for a quite large number to reserve memory for?

[gavanderhoorn]

Question: would using an RT-safe memory allocator not be a more scalable approach?

[mergify]

This pull request is in conflict. Could you fix it @saikishor?