refactor: [DX-2625] update examples to use Unified SDK

[CodeSchwert]

Summary

Update imx-examples to finally use the latest SDK!

• Swapped out SDK JS for the Unified SDK
• Added a minting step with easier to use minting script (no more having to update token ID's manually in .env 🙌)
• Reduced the number of environment variables required
• Removed all the unnecessary admin scripts
• Added / refactored helper scripts to get collection and asset data
• Removed lots of unused dependencies and accompanying code

Why the changes

imx-sdk-js has been deprecated, and this update was way long overdue!!!

Things worth calling out

@immutable/sdk is now the code owner... might not be the most appropriate team to own this.