Remove or refactor 'USystemDataBuilder' class

[andygruening]

I saw it's not used anywhere, but it's a nice feature to collect everything into one struct. Though I'd vote for removing it, there are already functions to get data like chain id, wallet address etc.

Reasons:

• Async functions like QR Code or getting transaction history didn't work, saying 'resulting in a soft lock'
• Requiring to load QR texture into the level no-matter-what is memory hungry