Extend default native fields option

[hacknug]

This PR adds most of the default native fields discussed in #3.

Breaking Changes

• The Custom option now requires you to write a valid CSS selector instead of just the ID of the element. This change has been introduced to explicitly acknowledge users can select multiple metaboxes to move at once. Previously it would've required them to write something like first-id, #second-id.

Other Changes

• Options inside the native select element are now grouped by category (Core, WooCommerce, Plugins, and Other)
• Options from the WooCommerce and Plugins categories are now shown only when the required plugin is active (not just installed)
• Instead of having a common option for both Yoast SEO and The SEO Framework, they now have independent options

[marcusforsberg]

@hacknug Thanks! I'm interested in merging this if you have the time to resolve the conflicts by re-doing this on a fresh checkout. Please ensure you have Prettier installed so the code is formatted as per our standards.