Apply particle scattering effect to lidars

[iche033]

depends on #251

Summary

Lidars detect particles as large blocky squares due to the way particles are rendered in ogre (2d sprites / billboard). This PR applies scattering effect in a similar way as it's done for the depth camera in pull request #251. Whenever a ray in the lidar intersects with a particle, there is a chance that it'll miss or become scattered (by adding Gaussian noise).

Test it

• Launch ign-gazebo with this sensor_particles.sdf world.
• Open the Visualize Lidar gui plugin (open top right menu and select Visualize Lidar
• Hit refresh button next to the topic drop down list in the Visualize Lidar plugin to see the /lidar topic
• Hit Play to see lidar visualization.

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• 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

Note to maintainers: Remember to use Squash-Merge

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (depth_particles@733bc91). Click here to learn what that means.
The diff coverage is n/a.

@@                Coverage Diff                 @@
##             depth_particles     #252   +/-   ##
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  Coverage                   ?   54.02%           
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  Files                      ?      143           
  Lines                      ?    13917           
  Branches                   ?        0           
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  Hits                       ?     7518           
  Misses                     ?     6399           
  Partials                   ?        0           

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[adlarkin]

Left a lot of comments that are similar to #251. I tested the example world, and it worked for me. My level of understanding of this PR is similar to the level of understanding for #251, so it might be worth having someone else review this if they're reviewing #251 as well.

[adlarkin]

As I mentioned before, my understanding of what's going on here isn't perfect, so if someone else wants to take a look as well, go for it, but this looks good to me.