Fix Layout Builder compatibility for Media Gallery

I am currently working on this locally but it is dependent ✨ Replace hardcoded Media Photoswipe view mode with configurable formatter Active being merged.

I think needs to add a test for this functionality (MG + LB)

Is this AI generated code? :D

I wish. I had to struggle a lot to to get this working :). 95% of it is my own hard work. Sometimes I ask AI how to accomplish certain tasks. On this specific PR, I had AI help me clean up the variable names in `getLayoutBuilderImagesField` to more appropriately align with the Layout Builder terminology.

I think needs to add a test for this functionality (MG + LB)

Sounds like a good idea. I will begin working on tests to cover the changes.

I have improved the test code coverage for the Layout builder compatibility.

@ivnish, I used xdebug code coverage to verify that the test cases were hitting all relevant code branches. While I was researching on Drupal code coverage, I saw other modules who have integrated code coverage into their pipelines. Is this something you would want to do? See example here: https://www.drupal.org/project/knowledge/issues/3526796 📌 Add Code Coverage Active