Encode directly from string in one step only

[baumblatt]

Actually the Encode node receive only a word array as payload that is obtained easily decoding a string with Decode node.

But is a little bit tedious to decode a string just to encode it as Base64 for example.

This issue is to enhance the Encode and Decode node to do a combo of decode/encode in only one step without remove the ability to do just one of the actions.