Groundwork for integrating Specta (#949)

* add derive(specta::Type)

* use specta from git

* introduce Uuid type

* remove unnecessary specta::Type

* document export_types test

* upgrade Specta
The previous Specta branch had some hacks that were just for this project. They have all been converted into proper features so they can be merged into main.

* remove some unnecessary specta::Type uses

* add MessageDiscriminantDef explanation

* manually export types with specta

* rename 'specta.rs' to 'export_types.rs'

* rename 'export_types' to 'generate_ts_types'

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Co-authored-by: Oscar Beaumont <oscar@otbeaumont.me>

document-legacy/src/operation.rs

@@ -13,7 +13,7 @@ use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};
 
 #[repr(C)]
-#[derive(Debug, Clone, Deserialize, Serialize, PartialEq)]
+#[derive(Debug, Clone, Deserialize, Serialize, PartialEq, specta::Type)]
 // TODO: Rename all instances of `path` to `layer_path`
 /// Operations that can be performed to mutate the document.
 pub enum Operation {