Enable HIDE_SYMBOLS_BY_DEFAULT

[j-rivero]

🎉 New feature

Closes #

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.

[mjcarroll]

LGTM with green CI

[codecov]

Codecov Report

Merging #549 (767be55) into main (57b6f81) will not change coverage.
The diff coverage is n/a.

❗ Current head 767be55 differs from pull request most recent head 41999c9. Consider uploading reports for the commit 41999c9 to get more accurate results

@@           Coverage Diff           @@
##             main     #549   +/-   ##
=======================================
  Coverage   83.63%   83.63%           
=======================================
  Files          79       79           
  Lines       10213    10213           
=======================================
  Hits         8542     8542           
  Misses       1671     1671           

see 1 file with indirect coverage changes

[j-rivero]

Failing probably because of this #548 (comment) . I'm fixing it first.

[mjcarroll]

Included in #550