chore: extract event-emitter from core

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

packages/core/package.json

@@ -316,6 +316,7 @@
     "@k8slens/application-for-electron-main": "^6.5.0-alpha.0",
     "@k8slens/button": "^1.0.0-alpha.5",
     "@k8slens/error-boundary": "^1.0.0-alpha.5",
+    "@k8slens/event-emitter": "^1.0.0-alpha.1",
     "@k8slens/resizing-anchor": "^1.0.0-alpha.5",
     "@k8slens/routing": "^1.0.0-alpha.5",
     "@k8slens/cluster-settings": "^6.5.0-alpha.1",