Cleanup: Remove polkadot-service dependency from minimal node (#2430)

* Remove polkadot-service dependency from minimal-node

* Clean up error handline

* Remove unwanted changes

* Unused deps

client/relay-chain-interface/src/lib.rs

@@ -46,7 +46,9 @@ pub enum RelayChainError {
 	WaitTimeout(PHash),
 	#[error("Import listener closed while waiting for relay-chain block `{0}` to be imported.")]
 	ImportListenerClosed(PHash),
-	#[error("Blockchain returned an error while waiting for relay-chain block `{0}` to be imported: {1}")]
+	#[error(
+		"Blockchain returned an error while waiting for relay-chain block `{0}` to be imported: {1}"
+	)]
 	WaitBlockchainError(PHash, sp_blockchain::Error),
 	#[error("Blockchain returned an error: {0}")]
 	BlockchainError(#[from] sp_blockchain::Error),
@@ -86,6 +88,12 @@ impl From<RelayChainError> for sp_blockchain::Error {
 	}
 }
 
+impl<T: std::error::Error + Send + Sync + 'static> From<Box<T>> for RelayChainError {
+	fn from(r: Box<T>) -> Self {
+		RelayChainError::Application(r)
+	}
+}
+
 /// Trait that provides all necessary methods for interaction between collator and relay chain.
 #[async_trait]
 pub trait RelayChainInterface: Send + Sync {