refactor: rearrange definitions

Moves struct definitions and impls closer together to make reading
easier

Author: secona

crates/cargo-util-schemas/src/lockfile.rs

@@ -20,14 +20,14 @@ pub struct TomlLockfile {
     pub patch: TomlLockfilePatch,
 }
 
+pub type TomlLockfileMetadata = BTreeMap<String, String>;
+
 #[derive(Serialize, Deserialize, Debug, Default)]
 #[cfg_attr(feature = "unstable-schema", derive(schemars::JsonSchema))]
 pub struct TomlLockfilePatch {
     pub unused: Vec<TomlLockfileDependency>,
 }
 
-pub type TomlLockfileMetadata = BTreeMap<String, String>;
-
 impl TomlLockfilePatch {
     fn is_empty(&self) -> bool {
         self.unused.is_empty()