Fixing Singleton typing to correctly return child class (#1914)

- Add distinction between `getInstance` and `getInstanceOrCreate` since
  it is not always possible to create an instance (since you might not
  know the correct arguments)

- Remove all the `export const *Store = *Store.getInstance<*Store>();`
  calls as it defeats the purpose of `Singleton`. Plus with the typing
  changes the appropriate `*Store.getInstance()` is "short enough".

- Special case the two extension export facades to not need to use
  `getInstanceOrCreate`. Plus since they are just facades it is always
  possible to create them.

- Move some other types to be also `Singleton`'s: ExtensionLoader,
  ExtensionDiscovery, ThemeStore, LocalizationStore, ...

- Fixed dev-run always using the same port with electron inspect

- Update Store documentation with new recommendations about creating
  instances of singletons

- Fix all unit tests to create their dependent singletons

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/renderer/components/+storage-volume-claims/volume-claim-details.tsx

@@ -15,7 +15,7 @@ import { getDetailsUrl, KubeObjectDetailsProps, KubeObjectMeta } from "../kube-o
 import { PersistentVolumeClaim } from "../../api/endpoints";
 import { kubeObjectDetailRegistry } from "../../api/kube-object-detail-registry";
 import { ResourceType } from "../cluster-settings/components/cluster-metrics-setting";
-import { clusterStore } from "../../../common/cluster-store";
+import { ClusterStore } from "../../../common/cluster-store";
 
 interface Props extends KubeObjectDetailsProps<PersistentVolumeClaim> {
 }
@@ -43,7 +43,7 @@ export class PersistentVolumeClaimDetails extends React.Component<Props> {
     const metricTabs = [
       "Disk"
     ];
-    const isMetricHidden = clusterStore.isMetricHidden(ResourceType.VolumeClaim);
+    const isMetricHidden = ClusterStore.getInstance().isMetricHidden(ResourceType.VolumeClaim);
 
     return (
       <div className="PersistentVolumeClaimDetails">

src/renderer/components/+storage-volume-claims/volume-claim-disk-chart.tsx

@@ -5,13 +5,13 @@ import { BarChart, ChartDataSets, memoryOptions } from "../chart";
 import { isMetricsEmpty, normalizeMetrics } from "../../api/endpoints/metrics.api";
 import { NoMetrics } from "../resource-metrics/no-metrics";
 import { IResourceMetricsValue, ResourceMetricsContext } from "../resource-metrics";
-import { themeStore } from "../../theme.store";
+import { ThemeStore } from "../../theme.store";
 
 type IContext = IResourceMetricsValue<PersistentVolumeClaim, { metrics: IPvcMetrics }>;
 
 export const VolumeClaimDiskChart = observer(() => {
   const { params: { metrics }, object } = useContext<IContext>(ResourceMetricsContext);
-  const { chartCapacityColor } = themeStore.activeTheme.colors;
+  const { chartCapacityColor } = ThemeStore.getInstance().activeTheme.colors;
   const id = object.getId();
 
   if (!metrics) return null;