Update setup for node-rpc

[brunomenezes]

📄 Context

The node-rpc setup to read data from L1 is completely attached to infura. The idea is to be able to swap to any other provider, e.g. Alchemy freely.

The problem is relevant, so it is quick to swap when any of these providers offer a better solution (i.e. price-wise or any other metric we see as appropriate).

The affected part is the wallet setup.

📈 Subtasks

• Add new env vars to set up a node-rpc-uri per network.
• Update the wallet network setup.

🎯 Definition of Done

• CI is passing
• Vercel builds are green