Expose rendering teardown event

[hidmic]

🎉 New feature

Follow-up after #1475. Turns out rendering sensor destruction must also occur in the rendering thread.

Summary

This patch adds a rendering::RenderTeardown event for downstream users to perform cleanup upon the rendering thread stopping.

Test it

...

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

Merging #1539 (2bc0931) into main (a3cbd8c) will decrease coverage by 0.02%.
The diff coverage is 65.00%.

❗ Current head 2bc0931 differs from pull request most recent head 69ec120. Consider uploading reports for the commit 69ec120 to get more accurate results

@@            Coverage Diff             @@
##             main    #1539      +/-   ##
==========================================
- Coverage   63.62%   63.60%   -0.03%     
==========================================
  Files         330      330              
  Lines       25787    25847      +60     
==========================================
+ Hits        16408    16439      +31     
- Misses       9379     9408      +29     

Impacted Files	Coverage Δ
include/gz/sim/Link.hh	100.00% <ø> (ø)
include/gz/sim/ServerConfig.hh	100.00% <ø> (ø)
include/gz/sim/Util.hh	100.00% <ø> (ø)
include/gz/sim/rendering/SceneManager.hh	100.00% <ø> (ø)
src/Link.cc	94.77% <ø> (ø)
.../plugins/component_inspector/ComponentInspector.cc	5.49% <ø> (ø)
.../plugins/component_inspector/ComponentInspector.hh	28.57% <ø> (ø)
src/rendering/MarkerManager.cc	13.02% <ø> (ø)
src/systems/physics/Physics.cc	64.52% <0.00%> (-0.33%)	⬇️
src/systems/thruster/Thruster.cc	91.77% <ø> (ø)
... and 13 more

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[arjo129]

LGTM

[hidmic]

@arjo129 small change to ensure custom rendering sensors that depend on builtin rendering sensors get destroyed first (not an issue right now, might become for someone else in the future).

[iche033]

just one minor comment otherwise looks good to me.

[hidmic]

@iche033 @arjo129 CI failures have nothing to do with this patch. How shall we go about this?

[chapulina]

CI failures have nothing to do with this patch. How shall we go about this?

Agreed. Feel free to merge, CI is unstable for this branch right now, no need to block this PR.