Dapp refresh (#5752)

* RwLock

* getting there

* argh

* parking_lot

* rpc

* wax on wax off

* almost there

* remove lock

* write over read

* works

* linting

* small updates

* dissapearing act

* router update

* complete

* one m

* grumbles1

* grumbles part II

* parking_lot->util

* missed test case

* fied package-lock.json

* small fixes

* 404 tests failing

* cleanup

* cleanup 2

* updates and the likes

* play

* simplify filter

* f-ing bugs

* read->write

* Address own grumbles.

* Fix test.

parity/dapps.rs

@@ -291,7 +291,7 @@ mod server {
 
 	pub fn service(middleware: &Option<Middleware>) -> Option<Arc<rpc_apis::DappsService>> {
 		middleware.as_ref().map(|m| Arc::new(DappsServiceWrapper {
-			endpoints: m.endpoints()
+			endpoints: m.endpoints().clone(),
 		}) as Arc<rpc_apis::DappsService>)
 	}
 
@@ -313,5 +313,10 @@ mod server {
 				})
 				.collect()
 		}
+
+		fn refresh_local_dapps(&self) -> bool {
+			self.endpoints.refresh_local_dapps();
+			true
+		}
 	}
 }