Broadcasts to Posts: Import Thumbnail Setting

[n7studios]

Summary

Adds an option to enable / disable importing the Broadcast's thumbnail to the WordPress Post's Featured Image, enabled by default.

Previously, a Broadcast's thumbnail would be set as the WordPress Post's Featured Image.

Testing

• testBroadcastsImportWithImportThumbnailDisabled: Test that no thumbnail is set as the Featured Image when the Import Thumbnail setting is disabled.
• Other broadcast tests updated to check thumbnail is set as the Featured Image; GitHub action file permissions updated to allow WordPress to store imported images in the filesystem

Checklist

• I have written a test and included it in this PR
• I have run all tests and they pass
• The code passes when running the PHP CodeSniffer
• Code meets WordPress Coding Standards for PHP, HTML, CSS and JS
• Security and Sanitization requirements have been followed
• I have assigned a reviewer or two to review this PR (if you're not sure who to assign, we can do this step for you)

[noelherrick]

Does the user need execute on these files? This chmod includes that.

[n7studios]

Removing the executable permission results in tests not being able to run, and e.g. log files not being writable/modified:

These permissions are expansive, but it seems to be the best way to permit the tests and WordPress access to writing to e.g. the Media Library uploads folder (link)