chore: Extract sidebar item injection token into separate package

- Add unit tests to cover custom resources sidebar items

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

open-lens/src/main/index.ts

@@ -25,13 +25,14 @@ runInAction(() => {
   registerLensCore(di, environment);
 
   registerFeature(di,
-      loggerFeature,
+    loggerFeature,
   );
 
-  registerFeature(di,
-      applicationFeature,
-      applicationFeatureForElectronMain,
-      messagingFeatureForMain,
+  registerFeature(
+    di,
+    applicationFeature,
+    applicationFeatureForElectronMain,
+    messagingFeatureForMain,
   );
 
   try {