addition error definitions (#2107)

* remove low information density error doc comments

* another round of error dancing

* fix compilation

* remove stale `None` argument

* adjust test, minor slip in command

* only add AvailabilityError for full node features

* another None where none shuld be

polkadot/node/test/service/src/lib.rs

@@ -28,7 +28,7 @@ use polkadot_primitives::v1::{
 };
 use polkadot_runtime_common::BlockHashCount;
 use polkadot_service::{
-	NewFull, FullClient, ClientHandle, ExecuteWithClient, IsCollator,
+	Error, NewFull, FullClient, ClientHandle, ExecuteWithClient, IsCollator,
 };
 use polkadot_node_subsystem::messages::{CollatorProtocolMessage, CollationGenerationMessage};
 use polkadot_test_runtime::{
@@ -45,7 +45,6 @@ use sc_network::{
 };
 use service::{
 	config::{DatabaseConfig, KeystoreConfig, MultiaddrWithPeerId, WasmExecutionMethod},
-	error::Error as ServiceError,
 	RpcHandlers, TaskExecutor, TaskManager,
 };
 use service::{BasePath, Configuration, Role};
@@ -76,14 +75,14 @@ pub fn new_full(
 	is_collator: IsCollator,
 ) -> Result<
 	NewFull<Arc<Client>>,
-	ServiceError,
+	Error,
 > {
 	polkadot_service::new_full::<polkadot_test_runtime::RuntimeApi, PolkadotTestExecutor>(
 		config,
 		is_collator,
 		None,
 		polkadot_parachain::wasm_executor::IsolationStrategy::InProcess,
-	).map_err(Into::into)
+	)
 }
 
 /// A wrapper for the test client that implements `ClientHandle`.