Grafana integration (#3913)

* Very WIP

* record_metrics macro works

* Integrate into service

* Licenses and documentation

* Remove unused Debugs, make respond function clearer

* Conform to line widths, fix service test

* Switch to storing the timestamps as millis instead

* Update core/grafana-data-source/src/lib.rs

Co-Authored-By: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Transform timestamps to i64 in serialization

* Fix license date

* Binary sort to find selection range for metrics

* Obey maxDataPoints

* Run a cleaning future

* Newlines at EOF

* Update core/service/Cargo.toml

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* Update core/grafana-data-source/src/lib.rs

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* Fix indentation

* Improve select_points

* Made test more accurate

* Inprogress

* Use the same futures version as hyper for now

* Error handling

* Remove dependence on hyper's tokio feature

* Added target_os flag

* Update Cargo.toml

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* Simplify example

* Remove compat wildcard

* Updated lock file

* Fix indentation 😉

substrate/client/service/test/src/lib.rs

@@ -190,6 +190,7 @@ fn node_config<G, E: Clone> (
 		rpc_ws: None,
 		rpc_ws_max_connections: None,
 		rpc_cors: None,
+		grafana_port: None,
 		telemetry_endpoints: None,
 		telemetry_external_transport: None,
 		default_heap_pages: None,