Add nonfungibles::Create Trait & Implement for Uniques (#9438)

* Add nonfungibles::Create Trait & Implement for Uniques

Closes #9419

* Formatting

* Remove default implementation (`TokenError::Unsupported`) from `Create` trait

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Formatting

* Do not wrap parameters in Options

* Formatting

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/frame/uniques/src/functions.rs

@@ -48,6 +48,38 @@ impl<T: Config<I>, I: 'static> Pallet<T, I> {
 		Ok(())
 	}
 
+	pub(super) fn do_create_class(
+		class: T::ClassId,
+		owner: T::AccountId,
+		admin: T::AccountId,
+		deposit: DepositBalanceOf<T, I>,
+		free_holding: bool,
+		event: Event<T, I>,
+	) -> DispatchResult {
+		ensure!(!Class::<T, I>::contains_key(class), Error::<T, I>::InUse);
+
+		T::Currency::reserve(&owner, deposit)?;
+
+		Class::<T, I>::insert(
+			class,
+			ClassDetails {
+				owner: owner.clone(),
+				issuer: admin.clone(),
+				admin: admin.clone(),
+				freezer: admin.clone(),
+				total_deposit: deposit,
+				free_holding,
+				instances: 0,
+				instance_metadatas: 0,
+				attributes: 0,
+				is_frozen: false,
+			},
+		);
+
+		Self::deposit_event(event);
+		Ok(())
+	}
+
 	pub(super) fn do_mint(
 		class: T::ClassId,
 		instance: T::InstanceId,