Create an interface in Wallet to send transactions

[digorithm]

Contracts already can send transactions but we need a way to send "standalone" transactions. For instance, how it's done with ethers.js:

walletSigner.sendTransaction(tx).then((transaction) => {
// ...
})

We should extend fuels-signers's Wallet abstraction to include this functionality.

Here's a more complete reference for how it could look like: https://ethereum.org/en/developers/tutorials/send-token-etherjs/