Remove bounding box when model is deleted

[chapulina]

🦟 Bug fix

Summary

Currently, when a selected model is deleted, its bounding box is not deleted and moves to the origin:

With this PR, the box is correctly deleted.

Checklist

• Signed all commits for DCO
• Added tests: nothing in rendering has unit tests right now. We should add some.
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

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[codecov]

Codecov Report

Merging #675 (1b446fb) into ign-gazebo4 (58cc8d3) will decrease coverage by 0.05%.
The diff coverage is 0.00%.

@@               Coverage Diff               @@
##           ign-gazebo4     #675      +/-   ##
===============================================
- Coverage        65.01%   64.96%   -0.06%     
===============================================
  Files              232      232              
  Lines            16645    16649       +4     
===============================================
- Hits             10822    10816       -6     
- Misses            5823     5833      +10     

Impacted Files	Coverage Δ
src/rendering/RenderUtil.cc	42.11% <0.00%> (-0.19%)	⬇️
src/SimulationRunner.cc	92.88% <0.00%> (-1.07%)	⬇️

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