[Test Framework] Add ability to run expression tests in new framework

We need to run existing expression tests from new framework.
Should include:
* Ability to generate tests based on the "template" and testdata/inlinedata
* Ability to comparing with baseline (with ranges)

We should have a clean baseline-like API for expression tests.
[Existing expression tests API](https://github.com/dotnet/fsharp/blob/91d598e4770da4b0426f0d87c2a5f224193182f8/tests/service/ExprTests.fs)
[New baseline tests API](https://github.com/dotnet/fsharp/blob/master/tests/FSharp.Compiler.ComponentTests/ConstraintSolver/PrimitiveConstraints.fs#L16)

@abelbraaksma FYI. Please, also free to add anything that I've missed :)