Await until the given condition evaluates to true or until a timeout

The timeout is taken from the innermost enclosing `within` block (if inside a `within` block) or the value specified in config value "akka.test.single-expect-default". The value is dilated, i.e. scaled by the factor specified in config value "akka.test.timefactor"..

A call to conditionIsFulfilled is done immediately, then the threads sleep for about a tenth of the timeout value, before it checks the condition again. This is repeated until timeout or the condition evaluates to true. To specify another interval, use the overload AwaitCondition(Func<Boolean>, Nullable<TimeSpan>, Nullable<TimeSpan>, String)