Fix invalid signatures produced by signMultiSignatureTransactionWithPrivateKey

[ManuGowda]

Expected behavior

signMultiSignatureTransactionWithPrivateKey should include correct signatures according to keys.

Actual behavior

signMultiSignatureTransactionWithPrivateKey overrides signatures

When second person (not original sender) use signMultiSignatureTransactionWithPrivateKey with includeSenderSignature, it overwrites the transaction.signatures[0]

Steps to reproduce

1. Register a multi-signature account (e.g 2 mandatory)
2. Sign a multi-signature registration transaction from account1
3. Sign a multi-signature registration transaction from account2
4. Observe the signatures of account1 is replaced with account2

Additional information

This issue can be resolved by

1. Get public key from const signerPublicKey = lisk_cryptography_1.getPublicKey(privateKey);
2. Update public key check

if (includeSenderSignature &&
        Buffer.isBuffer(transactionObject.senderPublicKey) &&
        signerPublicKey.equals(transactionObject.senderPublicKey)
    ) {
        transactionObject.signatures[0] = signature;
    }
    const mandatoryKeyIndex = keys.mandatoryKeys.findIndex(aPublicKey => aPublicKey.equals(signerPublicKey));
    const optionalKeyIndex = keys.optionalKeys.findIndex(aPublicKey => aPublicKey.equals(signerPublicKey));
    if (mandatoryKeyIndex !== -1) {

Which version(s) does this affect? (Environment, OS, etc...)

5.2.0