Freeze NFT accounts

Mint accounts may also contain a freeze_authority (freeze Account) that can be used to issue instructions that render the account unusable.

Any write instruction containing a token that freezes the account will fail until the account is unfrozen using the mint account Thaw instruction.

The SetAuthority instruction can be used to change the mint's freeze_authority.

If the Mint account freeze_authority is set to None, the mint_authority account will be used by default to exercise freeze authority.

If freeze_authority is not None, using mint_authority for freeze operations will not take effect.

In addition, mint_authority can modify the freeze_authority of the mint account.