[BugBash] Support media entity.

[v-fenguo]

1. Add hasStream property for media entity in YAML, JSON and SWAGGER.
2. In C# client CodeGen, for media entity type, add HasStream attribute in class definition, for example:
   [global::Microsoft.OData.Client.HasStream()]
   public partial class Photo : global::Microsoft.OData.Client.BaseEntityType, global::System.ComponentModel.INotifyPropertyChanged
   {...}