K8s add cluster lookup (#2571)

* Kubernetes plugins boilerplate

* pr feedback; check for k8s annotation

* temp

* fix config

* add example local setup

* dice rolelr

* rever yarn lock update

* forgotten prettier

* prettier again

* master lock

* update lock with k8s deps

* prettier

* router tests

* internal error

* fix package.json

* PR feedback

* more pr feedback

* rename component file

* kubernetes fetcher tests

* fix test

* option constructor

plugins/kubernetes/package.json

@@ -22,6 +22,7 @@
   "dependencies": {
     "@backstage/catalog-model": "^0.1.1-alpha.23",
     "@backstage/core": "^0.1.1-alpha.23",
+    "@backstage/plugin-kubernetes-backend": "^0.1.1-alpha.23",
     "@backstage/theme": "^0.1.1-alpha.23",
     "@material-ui/core": "^4.11.0",
     "@material-ui/icons": "^4.9.1",