Correctly show more general NFT asset-identifier-types

[mijoco-btc]

Describe the bug

Explorer expects the NFT index to be a simple UINT. With progress on SIP-013 for semi fungible tokens we should expect to see more general tuple asset-identifier-types like:

{ token-id: uint, owner: principal }

However the explorer displays this type as NaN.

Transaction ID (testnet) 0xd54b1372c3eceec22cae73e401e23e8fb97fd80efb5b89d233b656e4382e528e Address ST1NXBK3K5YYMD6FD41MVNP3JS1GABZ8TRVX023PT.thirteen-mint Block# 49744 Time stamp

To Reproduce Mint an NFT with a non uint asset-identifier-type

Expected behavior If the NFT key is either interpreted firstly as a UINT, if this fails, as a the Semi Fungible type { uint, principal } and if this fails as the string form of the repr of the identifier.

Screenshots n/a - see transaction id above.

Desktop (please complete the following information): n/a

Smartphone (please complete the following information):

• n/a

Additional context