Add new RPC method to get the chain type (#5576)

* Add new RPC method to get the chain type

This adds a new RPC method to get the chain type of the running chain.
The chain type needs to be specified in the chain spec. This should make
it easier for tools/UI to display extra information without needing to
rely on parsing the chain name.

* Update client/rpc-api/src/system/mod.rs

Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

* Primitive crate

* Feedback

Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com>

substrate/bin/node-template/node/src/chain_spec.rs

@@ -3,10 +3,10 @@ use node_template_runtime::{
 	AccountId, AuraConfig, BalancesConfig, GenesisConfig, GrandpaConfig,
 	SudoConfig, SystemConfig, WASM_BINARY, Signature
 };
-use sp_consensus_aura::sr25519::{AuthorityId as AuraId};
-use sp_finality_grandpa::{AuthorityId as GrandpaId};
-use sc_service;
+use sp_consensus_aura::sr25519::AuthorityId as AuraId;
+use sp_finality_grandpa::AuthorityId as GrandpaId;
 use sp_runtime::traits::{Verify, IdentifyAccount};
+use sc_service::ChainType;
 
 // Note this is the URL for the telemetry server
 //const STAGING_TELEMETRY_URL: &str = "wss://telemetry.polkadot.io/submit/";
@@ -42,6 +42,7 @@ pub fn development_config() -> ChainSpec {
 	ChainSpec::from_genesis(
 		"Development",
 		"dev",
+		ChainType::Development,
 		|| testnet_genesis(
 			vec![
 				authority_keys_from_seed("Alice"),
@@ -67,6 +68,7 @@ pub fn local_testnet_config() -> ChainSpec {
 	ChainSpec::from_genesis(
 		"Local Testnet",
 		"local_testnet",
+		ChainType::Local,
 		|| testnet_genesis(
 			vec![
 				authority_keys_from_seed("Alice"),