Implement Convert trait to convert between CPU and GPU images (#3194)

* Add upload texture trait

* Make convert trait use explicit converter

* Add gpu texture download implementation

* Add footprint to convert trait

* Cleanup texture upload / download

* Download wgpu textures aligned

* abstract texture download into converter helper

* rename module

not only doing uploads anymore
conversion looks like a ok name

* Remove into_iter call and intermediate vector allocation

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Co-authored-by: Timon Schelling <me@timon.zip>

node-graph/gcore/src/registry.rs

@@ -9,7 +9,7 @@ use std::sync::{LazyLock, Mutex};
 pub use graphene_core_shaders::registry::types;
 
 // Translation struct between macro and definition
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct NodeMetadata {
 	pub display_name: &'static str,
 	pub category: Option<&'static str>,