Separated orchid-host and orchid-extension

This is an architectural change that allows me to implment specifics first and generalize along observed symmetries in orchid-base

orchid-api-traits/src/lib.rs

@@ -9,4 +9,4 @@ pub use hierarchy::{
   Base, Extends, HierarchyRole, InHierarchy, Subtype, TLBool, TLFalse, TLTrue, UnderRoot,
   UnderRootImpl,
 };
-pub use relations::{MsgSet, Request};
+pub use relations::{Channel, MsgSet, Request};