Token type renaming

[jackcmay]

TODO: update js bindings

[jackcmay]

@mvines inline with what you were thinking too?

[mvines]

Nice. How about going a little further where:

1. state::TokenMint becomes just Mint
2. state::Account now becomes Token.

[jackcmay]

@mvines Looks like you are referring to the generated C file, what do you think about the Rust naming?

[jackcmay]

Could rename State::Account(Account) to State::Account(Token) but that doesn't seem better

[mvines]

Maybe this?

pub enum State {
    /// Unallocated state, may be initialized into another state.
    Unallocated,
    /// A token type and associated mint.
    TokenType(Mint),
    /// Some amount of tokens
    Token(TokenInfo),
    /// Invalid state, cannot be modified by the token program.
    Invalid,
}

I also kinda like how the ERC20 standard has a token name and token symbol strings in it (https://eips.ethereum.org/EIPS/eip-20). There's certainly room in the State::TokenType enum for those strings, since the Mint struct is much smaller than the TokenInfo. Name/symbol a little toyish, but it does allow for a generic explorer interface to display all known tokens -- which I think people in the space tend to like.

[jackcmay]

@mvines @CriesofCarrots Post commit reviews welcome :-)