Ruby 3 / Rails 7 compatiblity

[sbounmy]

• [x] Bump dependencies including eth 0.5X
• [x] Dockerized app
• [x] Fix specs
• [x] Replace Blockexplorer (API no working anymore) by blockstream ?
• [x] Fix cucumber

[sbounmy]

Currently having trouble with /address not returning detailed transactions' outputs https://github.com/janoside/btc-rpc-explorer/issues/439

We might need to look for another explorer blockchain.info (cant find their testnet anymore) or blockchair

[sbounmy]

would love to have your feedback @Sailias