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/cli/src/chain_spec.rs

@@ -27,7 +27,7 @@ use node_runtime::{
 };
 use node_runtime::Block;
 use node_runtime::constants::currency::*;
-use sc_service;
+use sc_service::ChainType;
 use hex_literal::hex;
 use sc_telemetry::TelemetryEndpoints;
 use grandpa_primitives::{AuthorityId as GrandpaId};
@@ -158,6 +158,7 @@ pub fn staging_testnet_config() -> ChainSpec {
 	ChainSpec::from_genesis(
 		"Staging Testnet",
 		"staging_testnet",
+		ChainType::Live,
 		staging_testnet_config_genesis,
 		boot_nodes,
 		Some(TelemetryEndpoints::new(vec![(STAGING_TELEMETRY_URL.to_string(), 0)])
@@ -338,6 +339,7 @@ pub fn development_config() -> ChainSpec {
 	ChainSpec::from_genesis(
 		"Development",
 		"dev",
+		ChainType::Development,
 		development_config_genesis,
 		vec![],
 		None,
@@ -364,6 +366,7 @@ pub fn local_testnet_config() -> ChainSpec {
 	ChainSpec::from_genesis(
 		"Local Testnet",
 		"local_testnet",
+		ChainType::Local,
 		local_testnet_genesis,
 		vec![],
 		None,
@@ -396,6 +399,7 @@ pub(crate) mod tests {
 		ChainSpec::from_genesis(
 			"Integration Test",
 			"test",
+			ChainType::Development,
 			local_testnet_genesis_instant_single,
 			vec![],
 			None,
@@ -410,6 +414,7 @@ pub(crate) mod tests {
 		ChainSpec::from_genesis(
 			"Integration Test",
 			"test",
+			ChainType::Development,
 			local_testnet_genesis,
 			vec![],
 			None,