Improve Error Dialog message for VDB deployment where source doesnt exist

In some cases, when a user tries to deploy a VDB where one of the SourceModel DS does not exist, the user is prompted whether to create the source.

I encountered a case though where an Error Dialog was displayed instead, with the message "No Connection Information in model xxx.xmi". For this case(Mongo) there is no CP available.

Attaching model project set to reproduce, and a screen shot of the dialog.

Message could be more informative, e.g. "The Data Source for model xxx.xmi cannot be found on server, and no CP information is available" or similar.