safe-apps-sdk: create and send reject transaction

[ovc-serega]

We need functionality that would allow us to reject an existing transaction in gnosis safe.Similar to creating and sending a transaction.

Or would allow you to send a gnosis-core-sdk created with rejectTransaction() in gnosis safe.

[mmv08]

@Graeme-Code, Richard pointed out that we needed to indicate that the transaction is proposed with a custom nonce, potentially overwriting other transactions. Can we evaluate this issue? https://github.com/gnosis/safe-react/issues/2904 can be related