[CM] Handle other exceptions while loading the controller plugin

[saikishor]

As of now, we are only handling the exceptions of the pluginlib::CreateClassException there are many other exceptions defined by the pluginlib, that might be also interesting to catch. I'm using std::exception as the main PluginlibException is derived from std::runtime_error and which is derived from std::exception, and this gives us way to be generic (https://github.com/ros/pluginlib/blob/jazzy/pluginlib/include/pluginlib/exceptions.hpp#L43)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 86.79%. Comparing base (f743bf4) to head (544f693).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
controller_manager/src/controller_manager.cpp	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1731      +/-   ##
==========================================
- Coverage   86.82%   86.79%   -0.03%     
==========================================
  Files         116      116              
  Lines       10701    10704       +3     
  Branches      979      979              
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  Hits         9291     9291              
- Misses       1059     1062       +3     
  Partials      351      351              

Flag	Coverage Δ
unittests	86.79% <0.00%> (-0.03%)	⬇️

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Files with missing lines	Coverage Δ
controller_manager/src/controller_manager.cpp	77.47% <0.00%> (-0.21%)	⬇️