Simplify kdl now that kinetic support is dropped

[ruffsl]

Otherwise the build fails for osrf/ros2:nightly (Ubuntu 20.04) due to the unimplemented virtual function.

Related: #233

[codecov]

Codecov Report

Merging #237 into master will increase coverage by 0.72%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #237      +/-   ##
==========================================
+ Coverage   46.63%   47.35%   +0.72%     
==========================================
  Files         122      143      +21     
  Lines       12740    13347     +607     
==========================================
+ Hits         5941     6321     +380     
- Misses       6799     7026     +227     

Impacted Files	Coverage Δ
..._kinematics_plugin/chainiksolver_vel_mimic_svd.hpp	28.57% <ø> (ø)
...e/src/parameterization/model_based_state_space.cpp	67.80% <0.00%> (-0.95%)	⬇️
...traint_samplers/src/constraint_sampler_manager.cpp	84.90% <0.00%> (-0.68%)	⬇️
...obot_model/include/moveit/robot_model/link_model.h	88.23% <0.00%> (-0.66%)	⬇️
...moveit/distance_field/propagation_distance_field.h	85.71% <0.00%> (-0.40%)	⬇️
...it/collision_detection/test_collision_common_pr2.h	99.67% <0.00%> (-0.33%)	⬇️
moveit_core/profiler/src/profiler.cpp	64.40% <0.00%> (-0.30%)	⬇️
moveit_core/robot_model/src/link_model.cpp	100.00% <0.00%> (ø)
...ore/constraint_samplers/src/constraint_sampler.cpp	100.00% <0.00%> (ø)
.../transforms/include/moveit/transforms/transforms.h	100.00% <0.00%> (ø)
... and 109 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9e6868a...a654ba3. Read the comment docs.

[henningkayser]

@ruffsl I updated this branch, simply removing the version check in moveit_kinematics The remaining functions where re-enabled with the MoveIt 1 sync. Since master is targeting Foxy only (see comment in #250) we should be all clear with this solution.