types: We have fields with different names for a single Core name

[tcharding]

We rename when Core uses non-Rusty names e.g., scriptPubkey becomes script_pubkey. Since we wrote this crate over a long time there is a good chance that different renames snuck in. E.g.e, desc is sometimes renamed and sometimes not.

    /// Inferred descriptor for the script. v23 and later only.
    #[serde(rename = "desc")]
    pub descriptor: Option<String>,

v19/blockchain/mod.rs:394:    /// An output descriptor
v19/blockchain/mod.rs:395:    pub desc: String,