Add functions for remove/remove all signatures

[jbair06]

Problem

Issued copied from JS SDK: https://github.com/hashgraph/hedera-sdk-js/pull/2491

Once a signature has been added via addSignature, there is no convenience method to remove the signature.

Removing signatures is helpful when a transaction has a signing account that has a large keylist with many thresholds. If all signatures added to the transaction result in a transaction too large to submit, then only the minimum number of signatures required to make the transaction valid should be added to the transaction.

Also, if a signature is added, the owner of the key might decide to revoke the signature. Without recreating the transaction and re adding all the signatures, this is not possible.

Solution

• Add removeSignature(publicKey/signature) method
• Add removeAllSignatures() method

These two convenience methods will be helpful to remove signatures as needed.

Review the solution in the JS SDK: https://github.com/hashgraph/hedera-sdk-js/pull/2491

Alternatives

No response