Rename FB Product Sets to Facebook Product Sets and change location

[ibndawood]

Changes proposed in this Pull Request:

Closes #2328

This PR:

• Renames FB Product Sets to Facebook Product Sets.
• Adds show_in_menu => false to register_taxonomy arguments. This would remove the Facebook Product Sets taxonomy from being displayed in Products > Facebook Product Sets.
• Removes all references to FB Product Sets inside code comments.
• Adds a private method to display the Product Sets menu item under Marketing. The method verifies if a connection has been established before adding the menu item under Marketing.
• Adds a method that would filter the parent_file to correctly display the parent menu and submenu page when Facebook Product Sets is selected

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

Screenshots:

The Facebook Product Set under Marketing Menu

The Facebook Product Set taxonomy page

Detailed test instructions:

1. Verify Facebook for WooCommerce plugin is installed and activated.
2. Verify that the store is not connected to Facebook yet.
3. Verify there is no FB Product Sets menu item in the Products menu of WP admin.
4. Verify there is no Facebook Product Sets menu item under the Marketing menu.
5. Connect the store to Facebook.
6. Verify the menu item Facebook Product Sets is present under the Marketing menu.
7. Verify there is no Facebook Product Sets menu item under the Products menu.
8. Click on the Facebook Product Sets menu and verify the taxonomy is referred to as Facebook Product Set in singular and plural wherever applicable.
9. Verify the correct parent menu and submenu is selected when viewing Facebook Product Set page.

Changelog entry

Update - FB Product Set name changed to Facebook Product Set
Add - Facebook Product Set under the Marketing menu

[rawdreeg]

Looks good. Thanks, @ibndawood.

Just a couple of items I'd fix before merging:

https://github.com/woocommerce/facebook-for-woocommerce/blob/514e4ed7d0bf0528bd9d6e25d690b1bbb36c890c/facebook-commerce.php#L116

This comment still has FB Product Set

https://github.com/woocommerce/facebook-for-woocommerce/blob/514e4ed7d0bf0528bd9d6e25d690b1bbb36c890c/includes/Admin.php#L208

here too. see screenshot

I will approve this so you can merge as soon as you are ready to :-)

[ibndawood]

Thank you @rawdreeg for the review. I can see I missed the lower cases. I'll fix this and shall merge. Thank you for catching this.