The fuels-ts typescript SDK has no awareness of to-be-spent transactions

fuels-ts is a library for interacting with Fuel v2. The typescript SDK has no awareness of to-be-spent transactions causing some transactions to fail or silently get pruned as they are funded with already used UTXOs. The problem occurs, because the `fund` function in `fuels-ts/packages/account/src/account.ts` gets the needed ressources statelessly with the function `getResourcesToSpend` without taking into consideration already used UTXOs. This issue will lead to unexpected SDK behaviour, such as a transaction not getting included in the `txpool` / in a block or a previous transaction silently getting removed from the `txpool` and replaced with a new one.