Add colors to all nodes in a graph, even if disconnected, and properly display hidden network imports (#1921)

* Get output/input types by iterating to proto node. Fix types when undoing/redoing

* Remove unused code

* Fix types not updating when modified

* Improve code quality

* Improve proto node type lookup

* Nits

* Fix crash when adding Extract

---------

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

node-graph/gcore/src/types.rs

@@ -140,6 +140,12 @@ pub enum Type {
 	Future(Box<Type>),
 }
 
+impl Default for Type {
+	fn default() -> Self {
+		concrete!(())
+	}
+}
+
 unsafe impl StaticType for Type {
 	type Static = Self;
 }