Westend: Fellowship Treasury (paritytech#2532)

Treasury Pallet Instance for the Fellowship in Westend Collectives.

In this update, we present a Treasury Pallet Instance that is under the
control of the Fellowship body, with oversight from the Root and
Treasurer origins. Here's how it is governed:
- the Root origin have the authority to reject or approve spend
proposals, with no amount limit for approvals.
- the Treasurer origin have the authority to reject or approve spend
proposals, with approval limits of up to 10,000,000 DOT.
- Voice of all Fellows ranked at 3 or above can reject or approve spend
proposals, with a maximum approval limit of 10,000 DOT.
- Voice of Fellows ranked at 4 or above can also reject or approve spend
proposals, with a maximum approval limit of 10,000,000 DOT.

Additionally, we introduce the Asset Rate Pallet Instance to establish
conversion rates from asset A to B. This is used to determine if a
proposed spend amount involving a non-native asset is permissible by the
commanding origin. The rates can be set up by the Root, Treasurer
origins, or Voice of all Fellows.

---------

Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: joepetrowski <joe@parity.io>

substrate/frame/treasury/src/benchmarking.rs

@@ -78,8 +78,7 @@ fn create_approved_proposals<T: Config<I>, I: 'static>(n: u32) -> Result<(), &'s
 		#[allow(deprecated)]
 		Treasury::<T, I>::propose_spend(RawOrigin::Signed(caller).into(), value, lookup)?;
 		let proposal_id = <ProposalCount<T, I>>::get() - 1;
-		#[allow(deprecated)]
-		Treasury::<T, I>::approve_proposal(RawOrigin::Root.into(), proposal_id)?;
+		Approvals::<T, I>::try_append(proposal_id).unwrap();
 	}
 	ensure!(<Approvals<T, I>>::get().len() == n as usize, "Not all approved");
 	Ok(())
@@ -163,6 +162,8 @@ mod benchmarks {
 	fn approve_proposal(
 		p: Linear<0, { T::MaxApprovals::get() - 1 }>,
 	) -> Result<(), BenchmarkError> {
+		let approve_origin =
+			T::ApproveOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;
 		create_approved_proposals::<T, _>(p)?;
 		let (caller, value, beneficiary_lookup) = setup_proposal::<T, _>(SEED);
 		#[allow(deprecated)]
@@ -172,8 +173,6 @@ mod benchmarks {
 			beneficiary_lookup,
 		)?;
 		let proposal_id = Treasury::<T, _>::proposal_count() - 1;
-		let approve_origin =
-			T::ApproveOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;
 
 		#[extrinsic_call]
 		_(approve_origin as T::RuntimeOrigin, proposal_id);
@@ -191,8 +190,7 @@ mod benchmarks {
 			beneficiary_lookup,
 		)?;
 		let proposal_id = Treasury::<T, _>::proposal_count() - 1;
-		#[allow(deprecated)]
-		Treasury::<T, I>::approve_proposal(RawOrigin::Root.into(), proposal_id)?;
+		Approvals::<T, _>::try_append(proposal_id).unwrap();
 		let reject_origin =
 			T::RejectOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;