Improve handling of the generic baggage fields (#5656)

* Parse generic baggage types more carefully to preserve inner structure

* Add example

* Way too many clones

* Allow multiple generic arguments for baggage fields

* Try to detect errors earlier

* Support more types for the baggage fields, get rid of the path constraint

polkadot/node/orchestra/examples/duo.rs

@@ -18,7 +18,7 @@
 //! A dummy to be used with cargo expand
 
 use orchestra::{self as orchestra, Spawner, *};
-use std::collections::HashMap;
+use std::{collections::HashMap, sync::Arc};
 mod misc;
 
 pub use self::misc::*;
@@ -61,7 +61,7 @@ impl<Context> Fortified {
 }
 
 #[orchestra(signal=SigSigSig, event=EvX, error=Yikes, gen=AllMessages)]
-struct Duo<T> {
+struct Duo<T, U, V, W> {
 	#[subsystem(consumes: MsgStrukt, sends: [Plinko])]
 	sub0: Awesome,
 
@@ -69,19 +69,21 @@ struct Duo<T> {
 	plinkos: GoblinTower,
 
 	i_like_pi: f64,
-	i_like_generic: T,
-	i_like_hash: HashMap<f64, f64>,
+	i_like_tuple: (f64, f64),
+	i_like_generic: Arc<T>,
+	i_like_hash: HashMap<(U, V), Arc<W>>,
 }
 
 fn main() {
 	use futures::{executor, pin_mut};
 
 	executor::block_on(async move {
-		let (orchestra, _handle): (Duo<_, f64>, _) = Duo::builder()
+		let (orchestra, _handle): (Duo<_, f64, u32, f32, f64>, _) = Duo::builder()
 			.sub0(AwesomeSubSys::default())
 			.plinkos(Fortified::default())
 			.i_like_pi(::std::f64::consts::PI)
-			.i_like_generic(42.0)
+			.i_like_tuple((::std::f64::consts::PI, ::std::f64::consts::PI))
+			.i_like_generic(Arc::new(42.0))
 			.i_like_hash(HashMap::new())
 			.spawner(DummySpawner)
 			.build()