restructure rcloud-base as a single base controller (#37)

* restructure rcloud-base as a single base controller
* updated master.rest
* moved sentry from internal to pkg as it is used by relay
* removing unused rpc and it's dependencies
* Fix usermgmt tests
* Don't redefine variables in rest file
Co-authored-by: Abin Simon <abin.simon@rafay.co>

pkg/controller/runtime/testdata/unstructured2.yaml

@@ -0,0 +1,7 @@
+apiVersion: "stable.example.com/v1"
+kind: CronTab
+metadata:
+  name: my-new-cron-object
+spec:
+  cronSpec: "* * * * */5"
+  image: my-awesome-cron-image2