Gen command improvements: Support for subresources and for defining namespace and name of generated roles

[agmimidi]

This MR provides the following additional functionality.

1. Enables the use of an additional flag for the gen command named --useSubresouces. When this is defined, then the gen command also includes Kubernetes subresources (e.g. pods/exec) when generating Roles or Cluster roles. To avoid breaking existing functionality, default behaviour is to have this flag disabled.
2. Enables the use of two additional flags named --roleName and --namespace to define the name of the generated (cluster)role and of the target namespace. If none is defines, default behaviour is maintained (name=myRole, namespace=myNamespace)

Example use of new flags

Only define namespace and name of Role
rbac-tool gen --roleName me --namespace mine --deny-resources=secrets.,services. --allowed-verbs=get,list --generated-type=Role

Include also subresources
rbac-tool gen --roleName me --namespace mine --deny-resources=secrets.,services. --allowed-verbs=get,list --generated-type=Role --useSubresources

Tested in an M1 Chip
out_no_subresources.txt
out_subresources_no_names.txt
out_subresources.txt

[gadinaor]

This PR removes support for generating cluster roles - is this intended? I'd rather add have this PR extend the existing behavior