Add serializer/deserializer api endpoint (through post)

[FlyingPig69]

Worth a shot....please bear with me as I explain this. I'm a VERY novice dev and work with python predominantly.

Box registers requires data to be serialized, but as a novice user (using python) I find serializing and deserialzing values is not working using python. (i tried this, https://github.com/sininen-taivas/ergo-numerals, but it's not returning the correct results).

To enable more rapid and easy development it would be great to have an endpoint on the node client itself to serialize/deserialize values (coll[bytes], coll[slong] etc).

This will make working with registers a lot easier in all tools.

In the same way we can use swagger/api to return blake2b hash can we have endpoints for serializing and deserializing byte register values?