Allow extensions to define cluster features (#1125)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

src/extensions/core-api/cluster-feature.ts

@@ -0,0 +1 @@
+export { ClusterFeature as Feature, ClusterFeatureStatus as FeatureStatus } from "../cluster-feature"

src/extensions/core-api/index.ts

@@ -10,11 +10,13 @@ import * as Store from "./stores"
 import * as Util from "./utils"
 import * as Registry from "../registries"
 import * as CommonVars from "../../common/vars";
+import * as ClusterFeature from "./cluster-feature"
 
 export let windowManager: WindowManager;
 
 export {
   EventBus,
+  ClusterFeature,
   Store,
   Util,
   Registry,

src/extensions/core-api/stores.ts

@@ -1 +1,2 @@
 export { ExtensionStore } from "../extension-store"
+export type { Cluster } from "../../main/cluster"