Subclient name conflicts with namespace by default

[JoshLove-msft]

If clientName decorator isn't used to name a client, i.e. just using namespace to define a subclient, the C# namespace and type name will conflict, leading to us adding an underscore to the namespace. It would be better to avoid this as this will be a fairly common scenario. One idea would be to always suffix the client with Client event for subclients. We do this already for top-level clients. Doing this would give us better evolvability if clientInitialization is used in the future for a particular subclient to allow it to be initialized independently. The downside is that we would have many more types suffixed with Client even for the case where only 1 of them is directly constructable.

[m-nash]

This would go against our guidelines here https://azure.github.io/azure-sdk/dotnet_introduction.html#dotnet-subclient-factory-methods-suffix.

Or we would need to change those guidelines.

[JoshLove-msft]

Maybe something we can change for unbranded libraries.