Function assert_type should do infer_set instead of infer

The function assert_type will currently call TypeCalculator#infer to infer the type of the given value. This means that a lot of information is lost. A hash is for instance reduced to a key and value type and the correlation between the keys and values are lost. This was OK when the assert_type had a very simplistic way of reporting a mismatch but today, when it uses the TypeMismatchDescriber, a call to TypeCalculator#infer_set will result in much better output when a mismatch is detected.

ACCEPTANCE CRITERIA

• That the actual mismatch is pointed out when it is in the details e.g. that the below shows that:

  assert_type(Struct[{ a => Integer, b => Boolean }], { a => hello, x => world })

  • a has wrong type
  • b is missing
  • there is no x in the struct