Add isTransactionReplaced method to SafeApiKit

[hubagaspar91]

Context / issue

I've been working with the Safe SDKs for the past weeks, and they're pretty great, but there's a feature I think is missing specifically from the SafeApiKit - to be able to easily tell if an arbitrary Safe transaction was replaced (rejected).

I have implemented a solution for this in our project, which is quite simple, and I'd be happy to open a PR that implements that in the SafeApiKit itself.

Proposed solution

Basically, my solution would be:

• Add an isTransactionReplaced or similarly named method to apiKit
• It takes a safeAddress and either a safeTxHash or a SafeMultisigTransactionResponse | SafeMultisigTransaction
• If a safeTxHash was provided, get the full transaction (apiKit.getTransaction(safeTxHash))
• After that, query all transactions with the same nonce
• If any is already executed, and has a different safeTxHash than what was provided, return true
• Else return false

Alternatives

Maybe there's already a way to get this info easily using apiKit, if there is, feel free to close this issue.