Fix passthrough controller to not read non-existing state_interfaces

[urfeex]

When specifying higher-order splines while no velocity or acceleration state interfaces are configured for the robot, the controller attempted to read from the non-existing interfaces. This PR adds a check whether those interfaces are actually configured before attempting to read from them.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 5.66%. Comparing base (1b121b7) to head (c84ed09).
Report is 412 commits behind head on main.

Files with missing lines	Patch %	Lines
...trollers/src/passthrough_trajectory_controller.cpp	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##            main   #1314      +/-   ##
========================================
+ Coverage   3.59%   5.66%   +2.07%     
========================================
  Files         13      31      +18     
  Lines        947    3072    +2125     
  Branches     152     375     +223     
========================================
+ Hits          34     174     +140     
- Misses       843    2896    +2053     
+ Partials      70       2      -68     

Flag	Coverage Δ
unittests	5.66% <0.00%> (+2.07%)	⬆️

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