Single Assembly resolver

[mxprshn]

Now in runner and test runner we have different code which resolves assemblies:

• https://github.com/VSharp-team/VSharp/blob/master/VSharp.Utils/AssemblyManager.fs for runner (and test renderer)
• and

  VSharp/VSharp.TestRunner/TestRunnerTool.cs

  Lines 17 to 34 in 2a3e2d9

  	private static Assembly TryLoadAssemblyFrom(object sender, ResolveEventArgs args)
  	{
  	var existingInstance = AppDomain.CurrentDomain.GetAssemblies().FirstOrDefault(assembly => assembly.FullName == args.Name);
  	if (existingInstance != null)
  	{
  	return existingInstance;
  	}
  	foreach (string path in _extraAssemblyLoadDirs)
  	{
  	string assemblyPath = Path.Combine(path, new AssemblyName(args.Name).Name + ".dll");
  	if (!File.Exists(assemblyPath))
  	return null;
  	Assembly assembly = Assembly.LoadFrom(assemblyPath);
  	return assembly;
  	}
  	return null;
  	}

  for test runner

In particular, this code loads assemblies into different contexts, which means that something can work fine in runner, but don't work in test runner, or vice versa.

So, we need to use a single assembly manager for the whole V#. This manager should load assemblies into separate context (like https://github.com/VSharp-team/VSharp/blob/master/VSharp.Utils/AssemblyManager.fs)