Refactor Collectables

[plexsoup]

A collectible should be like a zipped package. It should have a ResourceLoader containing an object for the player (eg: gun that shoots), and an object for the HUD inventory display (eg: magazine is a button that reloads the gun), and a resource containing path-names for save/load and cross-level persistence.

The key here is that the button and the playerScene should contain all the logic they need to function, which would be better than having a million match/case statements in player and HUD

[plexsoup]

This is not likely to happen, so we'll work with what we've got.