RoslynEvaluator ignores disabling referencing AppDomain assemblies.

[oleg-shilo]

When a Roslyn-based evaluator aggregates assemblies to be referenced by the script to compile, it needs to include the CLR standard assemblies like "".GetType().Assembly. It collects them from the AppDomain.Current. Though it also picks previously loaded script assemblies due to the inadequate filtering of appdomain assemblies.