Add $post or $post_id to the quick_edit_custom_box hook

[tomdevisser]

Right now when you're adding a custom box to quick edit, you can't set an existing value without using JavaScript, cause you don't have acces to the post. For a more elaborate explanation, see the User Contributed Notes, top one by stevenlinx: ​https://developer.wordpress.org/reference/hooks/quick_edit_custom_box/

It would be more elegant if we could just use the post within the hook I think.