Implement node graph gpu execution via vulkano and rust gpu (#870)

* Add Executor abstraction

* Resolve inputs for proto nodes by adding compose nodes

* Add infrastructure for compiling gpu code

* Integrate nodegraph gpu execution into graph-crafter

* Extract graphene core path from env vars

* Make Color struct usable for gpu code

node-graph/gcore/src/lib.rs

@@ -1,6 +1,4 @@
 #![no_std]
-#![cfg_attr(target_arch = "spirv", feature(register_attr), register_attr(spirv))]
-
 #[cfg(feature = "async")]
 extern crate alloc;
 
@@ -11,20 +9,18 @@ use async_trait::async_trait;
 
 pub mod generic;
 pub mod ops;
-pub mod raster;
 pub mod structural;
 pub mod value;
 
+#[cfg(feature = "gpu")]
+pub mod gpu;
+
+pub mod raster;
+
 pub trait Node<T> {
 	type Output;
 
 	fn eval(self, input: T) -> Self::Output;
-	fn input(&self) -> &str {
-		core::any::type_name::<T>()
-	}
-	fn output(&self) -> &str {
-		core::any::type_name::<Self::Output>()
-	}
 }
 
 trait Input<I> {