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>

node-graph/gcore/src/lib.rs

@@ -15,6 +15,7 @@ use async_trait::async_trait;
 pub mod generic;
 pub mod ops;
 pub mod structural;
+pub mod uuid;
 pub mod value;
 
 #[cfg(feature = "gpu")]