C# codegen support aggregate generation

[hamzajg]

**Current project generation: **

./
├── Example-designer-model.json
├── Example.sln
├── Io.Vlingo.Example.Demo
│   ├── Infrastructure
│   │   ├── Bootstrap.cs
│   │   └── Persistence
│   │       └── OrderStateAdapter.cs
│   ├── Io.Vlingo.Example.Demo.csproj
│   ├── Model
│   │   └── Order
│   │       ├── IOrder.cs
│   │       ├── OrderCreated.cs
│   │       ├── OrderEntity.cs
│   │       └── OrderState.cs
│   └── vlingo-actors.json
├── Io.Vlingo.Example.Demo.Tests
│   ├── Infrastructure
│   │   └── Persistence
│   │       └── MockDispatcher.cs
│   ├── Io.Vlingo.Example.Demo.Tests.csproj
│   └── Model
│       └── Order
│           └── OrderEntityTest.cs
└── README.md

10 directories, 14 files

TODO :

• Add Aggregate Protocol generation
• Add Entity generation
• Add Unit Test project generation
• Add Entity Unit Test generation
• Fix imports
• Fix unit test runtime exceptions
• Fix Multi Aggregate imports
• Fix Value Objects imports
• Add Entity State generation DateTime support