Add rarityscore to Collectibles and handle attribute changes on equip/unequip

[Reblixt]

Add a rarityscore property to Collectibles to represent their rarity. Additionally, define and implement logic for updating the rarityscore when an Collectibles is equipped with or unequipped from an attribute. Ensure that the system consistently recalculates or adjusts the rarity score based on attribute changes and document the approach taken for these updates.