Depreciate occurrences of nested namespace object

[krtkvrm]

There are many places where we are using both namespace.Namespace and NamespaceID. We had planned to only use IDs instead of using whole object

type Action struct {
	ID          string
	Name        string
	NamespaceID string
        Namespace   namespace.Namespace     // <- Depreciate this
	CreatedAt   time.Time
	UpdatedAt   time.Time
}

This should be depreciated from codebase as well as proto