Validate hashes before setting hashes in setTransactionHashes method

[peter279k]

As title, the hashes should be validated before setting the array hash in setTransactionHashes method.
And the setTransactionHashes method are available in some classes. It can checkout the following captured picture.

I think we can use the isArrayOfHashes to validate that hash is correct format.

It's related to issue #64 and PR #68 .