Extract PartialComponents into a type alias (#2767)

Pulling PartialComponents into a named `Service` type stops clippy
complaining about type complexity and also makes the type signatures a
little less scary to read.

There's two instances where we can't pull it out into a type because a
nightly feature has not yet been stabilised (E.g. the `imp Fn` isn't
stabilised in a type alias context here:
https://github.com/paritytech/polkadot-sdk/blob/d84e135bbfc366a17bb6b72d0fc9d09ee781ab8d/polkadot/node/service/src/lib.rs#L477
).

---------

Co-authored-by: Bastian Köcher <git@kchr.de>

cumulus/polkadot-parachain/src/service.rs

@@ -216,6 +216,16 @@ impl sc_executor::NativeExecutionDispatch for PeopleRococoRuntimeExecutor {
 	}
 }
 
+/// Assembly of PartialComponents (enough to run chain ops subcommands)
+pub type Service<RuntimeApi> = PartialComponents<
+	ParachainClient<RuntimeApi>,
+	ParachainBackend,
+	(),
+	sc_consensus::DefaultImportQueue<Block>,
+	sc_transaction_pool::FullPool<Block, ParachainClient<RuntimeApi>>,
+	(ParachainBlockImport<RuntimeApi>, Option<Telemetry>, Option<TelemetryWorkerHandle>),
+>;
+
 /// Starts a `ServiceBuilder` for a full service.
 ///
 /// Use this macro if you don't actually need the full service, but just the builder in order to
@@ -223,17 +233,7 @@ impl sc_executor::NativeExecutionDispatch for PeopleRococoRuntimeExecutor {
 pub fn new_partial<RuntimeApi, BIQ>(
 	config: &Configuration,
 	build_import_queue: BIQ,
-) -> Result<
-	PartialComponents<
-		ParachainClient<RuntimeApi>,
-		ParachainBackend,
-		(),
-		sc_consensus::DefaultImportQueue<Block>,
-		sc_transaction_pool::FullPool<Block, ParachainClient<RuntimeApi>>,
-		(ParachainBlockImport<RuntimeApi>, Option<Telemetry>, Option<TelemetryWorkerHandle>),
-	>,
-	sc_service::Error,
->
+) -> Result<Service<RuntimeApi>, sc_service::Error>
 where
 	RuntimeApi: ConstructRuntimeApi<Block, ParachainClient<RuntimeApi>> + Send + Sync + 'static,
 	RuntimeApi::RuntimeApi: sp_transaction_pool::runtime_api::TaggedTransactionQueue<Block>