Restructure GPU execution to model GPU pipelines in the node graph (#1088)

* Start implementing GpuExecutor for wgpu

* Implement read_output_buffer function

* Implement extraction node in the compiler

* Generate type annotations during shader compilation

* Start adding node wrapprs for graph execution api

* Wrap more of the api in nodes

* Restructure Pipeline to accept arbitrary shader inputs

* Adapt nodes to new trait definitions

* Start implementing gpu-compiler trait

* Adapt shader generation

* Hardstuck on pointer casts

* Pass nodes as references in gpu code to avoid zsts

* Update gcore to compile on the gpu

* Fix color doc tests

* Impl Node for node refs

node-graph/graph-craft/src/executor.rs

@@ -10,6 +10,7 @@ pub struct Compiler {}
 impl Compiler {
 	pub fn compile(&self, mut network: NodeNetwork, resolve_inputs: bool) -> impl Iterator<Item = ProtoNetwork> {
 		let node_ids = network.nodes.keys().copied().collect::<Vec<_>>();
+		network.resolve_extract_nodes();
 		println!("flattening");
 		for id in node_ids {
 			network.flatten(id);