fix: testnet gas

[estebanmino]

Fixes BX-1457 Figma link (if any):

What changed (plus any additional context for devs)

original sepolia issue was happening because we were using mainnet gas prices from meteorology, instead we should get gas fees from provider, so

• testnets are now getting fees directly from provider since they're not supported by meterology
• testnets and custom networks where we don't have meteorology support will get gas fees from provide (which is the case in prod rn) with the difference that now we're getting eip1559 gas fees from network if supported for better gas fees

Screen recordings / screenshots

What to test