Front end integration for Base

[FezBox]

Preparation:

what assets are on the chain?
XCall, AssetManager, bnUSD addresses? xChainId of the chain.
Update Manage wallets modal design for several EVM chains.
Todo:

Add xChainId and assets on xTokenMap
Update Manage wallets modal UI
Add the EVM Chain to Wallet UI
Add the EVM chain native token as collateral on the Home page
Fetch balances
Problems:

Switching chains