[JTC] Make most parameters read-only

[christophfroehlich]

This is the first part of implementing the suggestions from #394 to JTC.

I made all parameters read-only, which aren't updated anyways or shouldn't be reconfigureable like DoF.

Remaining dynamic parameters (open for discussion):

• allow_partial_joints_goal
• allow_integration_in_goal_trajectories
• allow_nonzero_velocity_at_trajectory_end
• start_with_holding (aren't updated yet but well be updated in on_active once [JTC] Activate update of dynamic parameters #761 is merged)
• gains: aren't updated yet, see [JTC] Activate update of dynamic parameters #761
• constraints (tolerances): aren't updated yet, see [JTC] Activate update of dynamic parameters #761

Changes to get the tests running again:

• The tests failed because they heavily relied on parameter reconfiguration -> Now use parameter overrides before initializing the node.
• I removed the yaml file from the test/config folder because it wasn't used at all
• I removed the use_local_param from the testable class, I think it made no difference (any more?)

[codecov-commenter]

Codecov Report

Merging #771 (f8bf3e8) into master (e7f9962) will decrease coverage by 4.90%.
Report is 366 commits behind head on master.
The diff coverage is 25.91%.

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Additional details and impacted files

@@            Coverage Diff             @@
##           master     #771      +/-   ##
==========================================
- Coverage   35.78%   30.88%   -4.90%     
==========================================
  Files         189        7     -182     
  Lines       17570      832   -16738     
  Branches    11592      505   -11087     
==========================================
- Hits         6287      257    -6030     
+ Misses        994      133     -861     
+ Partials    10289      442    -9847     

Flag	Coverage Δ
unittests	30.88% <25.91%> (-4.90%)	⬇️

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

Files Changed	Coverage Δ
...ontroller/test/test_load_diff_drive_controller.cpp	11.11% <0.00%> (ø)
...ive_controller/test/test_diff_drive_controller.cpp	12.66% <7.81%> (ø)
diff_drive_controller/src/odometry.cpp	42.16% <11.11%> (ø)
diff_drive_controller/src/speed_limiter.cpp	46.55% <11.11%> (ø)
...iff_drive_controller/src/diff_drive_controller.cpp	47.13% <46.94%> (ø)
...de/diff_drive_controller/diff_drive_controller.hpp	100.00% <100.00%> (ø)
...troller/include/diff_drive_controller/odometry.hpp	100.00% <100.00%> (ø)

... and 189 files with indirect coverage changes

[saikishor]

LGTM