[CommandInfo].get_CommandNamespace #335
Description
A CommandInfo should be able to get its namespace.
Its namespace should be all the content before the last valid namespace separator [\.\\/]
This cannot be named .Namespace in [CommandInfo], because a [CmdletInfo] has a Namespace (in this case .CommandNamespace should be the real Namespace)
Therefore, every other [CommandInfo] needs to have an alias property .Namespace.