http://stackoverflow.com/questions/18642693/deserialising-polymorphic-types-with-mongodb-c-sharp-driver.
MongoDB.Driver" Version="3.3.0
MongoDB.Driver.GridFS 已全部合并到MongoDB.Driver
<ItemGroup>
<PackageReference Include="MongoDB.Driver" Version="3.3.0" />
<!--<PackageReference Include="MongoDB.Driver.Core" Version="2.30.0" /> -->
<!--<PackageReference Include="MongoDB.Driver.GridFS" Version="2.30.0" /> -->
</ItemGroup>
IMongoQueryable<T> change to IQueryable<T>
https://www.mongodb.com/zh-cn/docs/drivers/csharp/v3.3/fundamentals/gridfs/
MongoDB.Driver" Version="2.30.0
<ItemGroup>
<PackageReference Include="MongoDB.Driver" Version="3.3.0" />
<PackageReference Include="MongoDB.Driver.Core" Version="2.30.0" />
<PackageReference Include="MongoDB.Driver.GridFS" Version="2.30.0" />
</ItemGroup>