Support for Quixel Megascans

The GameAssetManager supports now zip files from Quixel Megascans. To import them, right click on a collection -> import assets -> choose Quixel ZIP's and select the parent folder of your Quixel zips. 

It will parse the directories recursively. On import, it will extract the preview image from every zip file and parses the .json file inside. Then it will create Tags and Collections according to the data in the .json file.