Fix the exported interface naming in the chainable controllers

[saikishor]

Fix the exported interfaces naming from the chainable controllers to have a proper standard interface name so that they can chain easily with other controllers without major changes.

Needs: ros-controls/ros2_control#2038

[christophfroehlich]

Changes LGTM, and tested successfully with ros-controls/ros2_control_demos#710

[Juliaj]

LGTM.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.56%. Comparing base (6d681ef) to head (11149f6).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1528      +/-   ##
==========================================
+ Coverage   84.50%   84.56%   +0.05%     
==========================================
  Files         123      123              
  Lines       11295    11325      +30     
  Branches      948      950       +2     
==========================================
+ Hits         9545     9577      +32     
  Misses       1446     1446              
+ Partials      304      302       -2     

Flag	Coverage Δ
unittests	84.56% <100.00%> (+0.05%)	⬆️

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

Files with missing lines	Coverage Δ
...roller/test/test_ackermann_steering_controller.cpp	100.00% <100.00%> (ø)
...roller/test/test_ackermann_steering_controller.hpp	86.59% <ø> (ø)
.../test_ackermann_steering_controller_preceeding.cpp	100.00% <100.00%> (ø)
...dmittance_controller/src/admittance_controller.cpp	74.71% <100.00%> (ø)
...nce_controller/test/test_admittance_controller.cpp	100.00% <100.00%> (ø)
...ntroller/test/test_bicycle_steering_controller.cpp	100.00% <100.00%> (ø)
...ntroller/test/test_bicycle_steering_controller.hpp	83.11% <ø> (ø)
...st/test_bicycle_steering_controller_preceeding.cpp	100.00% <100.00%> (ø)
...iff_drive_controller/src/diff_drive_controller.cpp	75.07% <100.00%> (+0.30%)	⬆️
...ive_controller/test/test_diff_drive_controller.cpp	94.29% <100.00%> (-0.02%)	⬇️
... and 14 more

... and 2 files with indirect coverage changes

[christophfroehlich]

Great!