[RQT-JTC] Allow incomplete joint limits

[christophfroehlich]

Description

For faster review, I manually cherry-picked the changes regarding joint-limits from #1131
With #2254 and #2281 some of the changes were applied already, and the rest was not possible to be directly merged due to conflicts.
Also, the urdf_parser_py does not allow a <limit> tag without velocity limits, so I removed the respective fallback section.

Is this user-facing behavior change?

yes, but instead of crashing it should now gracefully try to do something useful and give warnings.

Did you use Generative AI?

GPT Codex 5.3

[codecov]

Codecov Report

❌ Patch coverage is 88.70968% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.63%. Comparing base (9f162e1) to head (977c5ef).

Files with missing lines	Patch %	Lines
...ajectory_controller/joint_trajectory_controller.py	0.00%	3 Missing ⚠️
...ajectory_controller/test/test_joint_limits_urdf.py	93.61%	3 Missing ⚠️
...t_joint_trajectory_controller/joint_limits_urdf.py	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2404      +/-   ##
==========================================
+ Coverage   85.60%   85.63%   +0.02%     
==========================================
  Files         148      148              
  Lines       15827    15885      +58     
  Branches     1339     1343       +4     
==========================================
+ Hits        13549    13603      +54     
- Misses       1792     1796       +4     
  Partials      486      486              

Flag	Coverage Δ
unittests	85.63% <88.70%> (+0.02%)	⬆️

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

Files with missing lines	Coverage Δ
...t_joint_trajectory_controller/joint_limits_urdf.py	73.41% <91.66%> (+3.85%)	⬆️
...ajectory_controller/joint_trajectory_controller.py	0.00% <0.00%> (ø)
...ajectory_controller/test/test_joint_limits_urdf.py	97.84% <93.61%> (-2.16%)	⬇️

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[christophfroehlich]

@lakhmanisahil I splitted the original PR, this one here is faster to review. As you have refactored the module recently, maybe you can have a quick look if that makes sense? Thank you!