feat: Add sign and send all transactions feature

[CCristi]

This pull request introduces a new feature for handling multiple transactions in the Solana blockchain.
The most important change include the addition of SolanaSignAndSendAllTransactionsFeature feature.

Currently SignAndSendTransactionFeature does support passing multiple transactions, but the interface is a bit cumbersome in the context of sending multiple transactions. In SignAndSendTransactionFeature, transaction send mode (parallel/serial) is configured on a per transaction basis, which creates ambiguity when user configures mixed sending modes in a list of transactions.

With SolanaSignAndSendAllTransactionsFeature, send mode is configure once for all passed transactions.

[jordaaash]

This looks good and is inline with previous discussion on #35

I think we should probably remove the mode option from SignAndSendTransactionInput, rename SignAndSendTransactionMode to SignAndSendAllTransactionsMode, and move that to here.

It's not actually used by SignAndSendTransaction so we shouldn't have it in two places. This is technically a breaking change but since there should be no implementing consumers of this I think it's fine to do it as a minor release.

@0xproflupin?