substrate: sysinfo: Expose failed hardware requirements (#2144)

The check_hardware functions does not give us too much information as to
what is failing, so let's return the list of failed metrics, so that callers can print 
it.

This would make debugging easier, rather than try to guess which
dimension is actually failing.

Signed-off-by: Alexandru Gheorghe <alexandru.gheorghe@parity.io>

cumulus/parachain-template/node/src/service.rs

@@ -255,10 +255,14 @@ async fn start_node_impl(
 		// Here you can check whether the hardware meets your chains' requirements. Putting a link
 		// in there and swapping out the requirements for your own are probably a good idea. The
 		// requirements for a para-chain are dictated by its relay-chain.
-		if !SUBSTRATE_REFERENCE_HARDWARE.check_hardware(&hwbench) && validator {
-			log::warn!(
-				"⚠️  The hardware does not meet the minimal requirements for role 'Authority'."
+		match SUBSTRATE_REFERENCE_HARDWARE.check_hardware(&hwbench) {
+			Err(err) if validator => {
+				log::warn!(
+				"⚠️  The hardware does not meet the minimal requirements {} for role 'Authority'.",
+				err
 			);
+			},
+			_ => {},
 		}
 
 		if let Some(ref mut telemetry) = telemetry {