Enable HIDE_SYMBOLS_BY_DEFAULT

[j-rivero]

🎉 New feature

Summary

Use the hidden visibility by default in preparation to make the change generally on Ionic using Part of gazebosim/gz-cmake#166

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)
• 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.

[codecov]

Codecov Report

Merging #116 (bc82919) into main (32e4019) will not change coverage.
The diff coverage is n/a.

❗ Current head bc82919 differs from pull request most recent head 513c4e2. Consider uploading reports for the commit 513c4e2 to get more accurate results

@@           Coverage Diff           @@
##             main     #116   +/-   ##
=======================================
  Coverage   80.11%   80.11%           
=======================================
  Files           8        8           
  Lines         342      342           
=======================================
  Hits          274      274           
  Misses         68       68           

[azeey]

I think this is a duplicate of #115.

[j-rivero]

I think this is a duplicate of #115.

arg, sorry.