Changeset 16143

#2522:

• migrated a lot of projects to .NET Standard 2.0
• added AppDomain.CurrentDomain.ApplyPolicy to Assembly.ReflectionOnlyLoad in PluginValidator to correctly load the System library
• deleted Properties folder from .NET Standard projects, because AssemblyInformation is saved in .csproj files now
• .NET Framework projects target now v4.7, because it is only possible to use .NET Standard libraries in v4.6 or higher
• removed System.Data.Linq from defaultAssemblies and DiscoverNamespaces in ProgrammableOperator, it is not supported in .NET Standard
• the Microsoft.Windows.Compatibility package is necessary for usage of PluginInfrastructure, we should probably switch to the System.Drawing.Common package when PluginInfrastructure is migrated to .NET Standard