Resolve ILVerify assembly references from `.deps.json`.

An obstacle of using ILVerify is that all references of the assembly must be explicitly specified on the command line. We could take advantage of the AssemblyDependencyResolver class and automatically find the references from the assembly's accompanying .deps.json file if it exists. This would make using ILVerify much more easy.

The main question is how to expose it to the user. A way I thought is to use it if we specify a new switch like --use-deps-json and also have specified only one input file and no --references. If the shape is agreed upon I can implement it.