Subdomain implementation requires unique subdomains

[the-frey]

Because subdomains are still NFTs, they have to be unique, yadda yadda

[the-frey]

kinda think this might be a thing for clients to solve, like by prefixing with the wallet address maybe (or short hash of that)

[the-frey]

although the simplest solution is still to allow for long subdomains with a validation on the root part

maybe this is a new function, mint_path, that calls mint under the hood but has some additional functionality.

validation:

• change to allow / character

on mint:

• validate / is present
• check sender is owner of root ~- check all intermediate parts resolve~

then clear any subdomains on send/xfer:

• find all tokens for owner
• find all that begin with token being xfer'd
• burn (?)

[the-frey]

probably do with #58