Add per-chain aggregate software/hardware telemetry (#464)

* Add per-chain aggregate software/hardware telemetry

* Fix tests' compilation

* Add extra comments for the `Counter` struct

* Replace the boolean argument with an enum

* Rename `replace_hwbench` to `update_hwbench`

* Move `Counter` into a separate file

* Move `ChainStatsCollator` to `chain_stats.rs`

* Fix incorrect key on the unknown table

* Improve types for the stats component; get rid of `any`

frontend/src/App.tsx

@@ -112,6 +112,7 @@ export default class App extends React.Component<{}, {}> {
       sortBy: this.sortBy.get(),
       selectedColumns: this.selectedColumns(this.settings.raw()),
       tab,
+      chainStats: null,
     });
     this.appState = this.appUpdate({});