validate whether promises are correctly awaited.

[OlafConijn]

if a statemachine is invokes as a typescript function, the compiler must throw an error if the call is awaited (synchronous invokes of statemachines are not supported).

if a lambda is invoked as a typescript function, the compiler must throw an error if the call is not awaited (until the following issue is implemented: https://github.com/OlafConijn/ts2asl/issues/27)