Add Google Poly and Sketchfab data search and import

[guillefix]

Add an option to search Google Poly and Sketchfab and spawn those items.

This can be done when the Bot is present in the world. There are tricks to make it work when the bot isn't present, but they are tricky, and I think not worth it for now.

For Google Poly we can use our own local database, while for Sketchfab we could use the API, or a local database.

We can make this for higher Datreon tiers