Update logic for AbstractDynamicLinqCustomTypeProvider.GetAssemblyTypesWithDynamicLinqTypeAttribute

[StefH]

#702

[philr]

For .NET Framework, this is changing from calling assembly.GetExportedTypes() to assembly.GetTypes(). That allows the ReflectionTypeLoadException to be handled, but changes the behaviour to returning all the types in the assembly instead of just the public types. I don't know if you were intending change that? If not, the result can be filtered down to just the public types.

.NET Standard changes from assembly.ExportedTypes to assembly.GetExportedTypes(). GetExportedTypes() won't ever throw ReflectionTypeLoadException according to the documentation. This should be changed to assembly.GetTypes() like the .NET Framework version of the code (and potentially filtered to just public types)?