Cache NFT type id and NFT id after initial creation

[MastaP]

Currently the NFT type id is hardcoded. Upon startup the service checks if type has already been created (if not, creates it) and also looks up the NFT of this type (if the configured wallet does not have it, mints the token). There are several ways some things might go wrong.

• If hardcoded type id is changed, upon restart/redeploy with the newer version, service will automatically switch to new NFT.
• If for some reason there are several NFTs of same type owned by the wallet, the service might start using a different NFT from what it was using before.