Make TokenScript loaded via scriptURI(), if it is via IPFS be displayed as having a verified signature

[JamesSmartCell]

When using scriptURI() if the script is located on IPFS it is assumed to be certified.

See https://eips.ethereum.org/EIPS/eip-5169#security-considerations

Using IPFS, the script location fixes the script integrity.

Refer to https://github.com/AlphaWallet/alpha-wallet-android/issues/2785

[JamesSmartCell]

This concerns the 'certified' lock graphic and text (if you click on it), which shows whether the TokenScript is signed or not.

If the script if from IPFS then it has full integrity and is effectively signed (because of the hashing mechanics).

[hboon]

Keep for later. Apparently needs more thinking and refactoring. We aren't showing the verified status at the moment any way.