Adds new RFComms system

[caguero]

🎉 New feature

Requires

• Add comms infrastructure #1416

Summary

This PR adds a radio frequency comms model atop comms infrastructure created in #1416.

Test it

• Run the tests.
• Run the example:

1. Launch Gazebo:

ign gazebo -v 4 <your_ws>/src/ign-gazebo/examples/worlds/rf_comms.sdf

2. Launch a subscriber:

ign topic -e -t addr2/rx

3. Launch a publisher:

cd <your_ws>/src/ign-gazebo/examples/standalone/comms
mkdir build && cd build
cmake ..
make
./publisher addr2

You should observe messages on the subscriber terminal.

CC @arjo129

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 and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

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[iche033]

ok I think the build issues and warnings are resolved. Homebrew, windows, and ubuntu CI builds look fine now. Test failures are unrelated.

[osrf-triage]

This pull request has been mentioned on Gazebo Community. There might be relevant details there:

https://community.gazebosim.org/t/new-releases-2022-04-27-fortress-citadel/1389/1