Fix/2370 fb sync status is incorrect for catalog visibility hidden

[rawdreeg]

Changes proposed in this Pull Request:

When a product's catalog visibility is set to hidden, the Facebook Sync status is incorrect in the Products list admin and edit. The product is not synced in Facebook. This is because the sync_enabled variable would not take into account product_should_sync status in order to determined the dropdown value.

Making this change also meant adding provision for catalog visibility being restored. I added a helper method in the ProductValidator class to check whether is product is valid without checking the sync field, as this would still contain old meta data.

Closes #2370.

Replace this with a good description of your changes & reasoning.

• Do the changed files pass phpcs checks? Please remove phpcs:ignore comments in changed files and fix any issues, or delete if not practical.

Detailed test instructions:

1. Create a product with catalog visibility hidden.
2. Check the status of Facebook Sync in Products in the admin panel. It shows "Do not sync."
3. Check the status of Facebook Sync in the Products Edit screen. It shows "Do not sync."
4. Set this catalog visibility back to show and check that the Facebook Sync is restored to "Sync and Show."

Changelog entry

Fix - Facebook Sync status is incorrect when a product has catalog visibility hidden

[ibndawood]

Thank you @rawdreeg for your changes. I have added some questions please review them.

[rawdreeg]

Thanks for the feedback. This is ready for another round of reviews.

[ibndawood]

Thank you @rawdreeg for the changes. The changes look good. I generated the build and tested the instructions in #2370. The issue resolved with the new build.