Node network subgraph editing (#1750)

* Breadcrumb visualization, nested network consistency, create definitions for Merge internal nodes

* Add index to network inputs, remove imports usage from flatten network

* Replace NodeOutput with NodeInput::Node

* Fully remove imports field, remove unnecessary identity nodes, move Output node to encapsulating network

* Replace previous_outputs with root_node, fix adding artboard/layer to empty network

* Import/Export UI nodes

* Display input/output types dynamically from compiled network

* Add LayerNodeIdentifer::ROOT_PARENT

* Prevent .to_node() on ROOT_PARENT

* Separate NodeGraphMessage and GraphOperationMessage

* General bug fixes with nested networks

* Change layer color, various bug fixes and improvements

* Fix disconnect and set node input for proto nodes and UI export node

* Dashed line to export for previewed node

* Fix deleting proto nodes and nodes that feed into export

* Allow modifications to nodes outside of nested network

* Get network from Node Id parameter

* Change root_node to previous_root_node

* Get TaggedValue from proto node implementation type when disconnecting

* Improve preview functionality and state

* Artboard position and delete children fix

* Name inputs/outputs based on DocumentNodeDefinition or type, fix new artboard/layer insertion

* replace "Link" with "Wire", adjust previewing

* Various bug fixes and improvements

* Modify Sample and Poisson-Disk points, fix incorrect input index and deleting currently viewed node

* Open demo artwork

* Fix opening already upgraded documents and refactor FrontendGraphDataType usages

* Fix deleting within network and other bugs

* Get default node input from compiled network when copying, fix previews, tests, demo artwork

* Code cleanup

* Hide EditorApi and add a comment describing unresolved Import node input types

* Code review

* Replace placeholder ROOT_PARENT NodeId with std::u64::MAX

* Breadcrumb padding

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Co-authored-by: Keavon Chambers <keavon@keavon.com>

node-graph/gstd/src/lib.rs

@@ -2,8 +2,8 @@
 #[macro_use]
 extern crate log;
 
-//pub mod value;
-//#![feature(const_type_name)]
+// pub mod value;
+// #![feature(const_type_name)]
 
 pub mod raster;