This commit adds a new API group called `infrastructure`.
This commit also contains some minor fixes in the code generator.

`infrastructure` API group introduces 4 new resources and their operations
(create, read, list, update, delete, etc.).
Resources are:
- GlobalInfrastructureProvider
  The `GlobalInfrastructureProvider` is an `infrastructure` non-namespaced resource that is available
  for all resources. It means, that `GlobalInfrastructureProvider` can be used for the LCM of every
  `Cluster` (namespaced) resource. Resource should contain the access data to the infrastructure
  provider instance.
- InfrastructureProvider
  The `InfrastructureProvider` is an `infrastructure` namespaced resource that is available
  only for resources from the same namespace. It means, that `InfrastructureProvider` can be
  used for LCM of `Cluster` resources from the same namespace.
  Resource should contain the access data to the infrastructure provider instance.
- GlobalCloud
  The `GlobalCloud` resource is an `infrastructure` non-namespaced resource that is available for
  all resources. It means, that `GlobalCloud` resource can be used by every `Application` (namespaced) resource.
- Cloud
  The `Cloud` resource is an `infrastructure` namespaced resource that is available only for
  resources from the same namespace. It means, that `Cloud` resource can be used by `Application`
  resources from the same namespace.

Issue #496



Signed-off-by: Matej Feder <matej.feder@dnation.cloud>