fix: fix unified markets query to include proper owner count

[juanmahidalgo]

This PR address the following things:

• The owners_count field was getting calculated on the JOIN with the opened orders, so it wasn't accurate. Now it's getting computed on all the NFTs joined with the items.
• Fixes the getIsOnSale condition: now it also has the logic for "not on sale", when there are no listings and it's either not on sale or sold out.
• For recently_listed, updates the logic and sorts by the greateast between max_order_created_at and first_listed_at, using the newest field to sort.
• For chepeast, updates the logic and sorts by first_listed_at as secondary field