Add basic support for NFT module

[ManuGowda]

LIP

• Introduce NFT module

Motivation

NFTs are very common in the blockchain space and have uses in a wide range of applications. This can go from being the virtual representation of a real world object (art, fashion, event tickets ...) to purely virtual collectibles (crypto kitties, ...).

Therefore, providing a unified module to handle, transfer and modify NFTs is a necessity for the Lisk ecosystem.

Tasks

TBD