Add securityContext and fix rabbitMQ cookie

[viktoriaas]

Issue introduces 2 problems together with a PR solving them.

1. Clusters with security policy enabled often forbid the usage of root. Therefore it is necessary to add optional securityContext to all deployments and to wes ConfigMap.

2. If rabbitMQ deployment is restarted (e.g. due to cluster failure) rabbitMQ cookie has incorrect permissions after restart ( rw-rw---- instead of rw-------). This is solved by chmod in main container before calling rabbitmq.