Refactor to .NET Core as it should be

[xhoogland]

Microsoft decided to have a few things backwards compatible with .NET Framework. Since this perhaps can break, just refactor this to what it should have been.

matrix/Services/GeneratorService.cs

Line 86 in aead8ca

var assemblies = AppDomain.CurrentDomain.GetAssemblies().SelectMany(a => a.GetTypes());