SerializerDescriptor relies on unsupported reflection API and will always throw

[ryalanms]

SerializerDescriptor needs to be updated to use System.Reflection.MetadataLoadContext.

(This is covered by internal test Avalon.Test.D2.Print.PluginSerializer.PluginSrzTestApp.)

[ryalanms]

After porting PluginSerializer.PluginSrzTestApp to .NET Core, the test is crashing while creating a SerializerProvider using its default constructor. The test doesn't make it to the SerializerDescriptor.

D:\PluginSerializer\PluginSrzTest\bin\Debug\net6.0-windows>PluginSrzTest.exe
Beginning Test *********************************************************
+Start Test: PluginSrzTestApp
Fail: EXCEPTION System.UriFormatException during test. Message: Invalid URI: The format of the URI could not be determined.. StackTrace:
Fail: at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind) in System.Private.Uri.dll:token 0x6000096+0x69
at System.Uri..ctor(String uriString) in System.Private.Uri.dll:token 0x600003d+0x14
at System.Windows.Xps.Serialization.XpsSerializerFactory.get_ManufacturerWebsite() in ReachFramework.dll:token 0x6000d86+0x0
at System.Windows.Documents.Serialization.SerializerDescriptor.CreateFromFactoryInstance(ISerializerFactory factoryInstance) in PresentationFramework.dll:token 0x6005d00+0x3e
at System.Windows.Documents.Serialization.SerializerProvider..ctor() in PresentationFramework.dll:token 0x6005d10+0xe
at Avalon.Test.D2.Print.PluginSerializer.PluginSrzTestApp.Run(CmdLineParser parser) in D:\PluginSerializer\PluginSrzTest\PluginSrzTest.cs:line 116
-End Test: PluginSrzTestApp Result: Fail