Add ->toBeOfType<<<__Enforceable>> reify T>() as an alternative ->toHaveType()

[lexidor]

->toHaveType() takes magic strings like numeric. This can not be supported as a reified generic, so it is not a replacement perse. This would subsume ->toBeInstanceOf(), but again, it is not meant as a replacement. instanceof is a relic from PHP so having a function with a less legacy sounding name for new tests can't be a bad thing.

Ergonomics, return T when done, for local refinement in the test.