Improve Code Generation Test Application

[JasonBock]

Describe the solution you'd like

• The application can take a fair amount of time to run, especially if the target assembly has thousands of mockable types. Granted, most of the work is just finding any possible type to mock, but I should look to see if there's a way to reduce the memory pressure.
• Provide more feedback/progress/status. It's better than what it was, but with large assemblies, it's not obvious what the progress is.
• May be interesting to use something like Spectre.Console to provide a nice experience.
• Partition the number of discovered types. For example, if the partition max size is set to 250, and I find 1,182 types in an assembly, then I create 5 partitions (using Spackle) and do each partition. That way, I'm not doing all 1,182 at once. Or, maybe once type discovery goes over the maximum, I run the tests on just those types, and then gather the next set. Not sure if this will help that much, but ... it might.

[JasonBock]

Probably a good reason to do this soon, as I just got this:

System.OutOfMemoryException: Insufficient memory to continue the execution of the program. at System.Reflection.Internal.StreamMemoryBlockProvider.ReadMemoryBlockNoLock(Stream stream, Int64 start, Int32 size) at System.Reflection.PortableExecutable.PEReader..ctor(Stream peStream, PEStreamOptions options, Int32 size) at Microsoft.CodeAnalysis.ModuleMetadata.CreateFromStream(Stream peStream, PEStreamOptions options) at System.Linq.Enumerable.ConcatIterator`1.MoveNext()