More reactive operators (tracking issue)

[akarnokd]

Proposed operators:

• Multi.defaultIfEmpty(T) ([Reactive] Implement defaultIfEmpty() + TCK tests #1520)
• Multi.defer(Supplier) ([Reactive] Implement defer() + TCK tests #1503)
• Multi.from(CompletionStage) ([Reactive] Reimplement Microprofile-RS, fix operators, add from(CS) #1511)
• Multi.from(Stream) ([Reactive] Implement from(Stream) + TCK tests #1525)
• Multi.interval() ([Reactive] Implement Multi.interval() + TCK tests #1526)
• Multi.observeOn ([Reactive] Implement observeOn + TCK tests #1546)
• Multi.reduce(BiFunction) ([Reactive] Implement reduce() + TCK tests #1504)
• Multi.reduce(Supplier, BiFunction) ([Reactive] Implement reduce() + TCK tests #1504)
• Multi.retry(long) ([Reactive] Implement retry() + TCK tests #1541)
• Multi.retry(BiPredicate<Throwable, Long>) ([Reactive] Implement retry() + TCK tests #1541)
• Multi.retryWhen(BiFunction<Throwable, Long, Publisher>) ([Reactive] Implement retry() + TCK tests #1541)
• Multi.switchIfEmpty(Publisher) ([Reactive] Implement switchIfEmpty + TCK tests #1527)
• Multi.takeUntil(CompletionStage) decided not to have a dedicated operator for this
• Multi.takeUntil(Publisher) ([Reactive] Implement takeUntil + TCK tests #1502)
• Multi.timeout() ([Reactive] Implement timeout() + TCK tests #1532)
• Multi.timer() ([Reactive] Implement timer() + TCK tests #1516)

---

• Single.defaultIfEmpty(T) ([Reactive] Implement defaultIfEmpty() + TCK tests #1520)
• Single.defer(Supplier) ([Reactive] Implement defer() + TCK tests #1503)
• Single.flatMapIterable(Function) ([Reactive] Implement Single.flatMapIterable + TCK tests #1517)
• Single.from(CompletionStage) ([Reactive] Reimplement Microprofile-RS, fix operators, add from(CS) #1511)
• Single.observeOn ([Reactive] Implement observeOn + TCK tests #1546)
• Single.retry(long) ([Reactive] Implement retry() + TCK tests #1541)
• Single.retry(BiPredicate<Throwable, Long>) ([Reactive] Implement retry() + TCK tests #1541)
• Single.retryWhen(BiFunction<Throwable, Long, Publisher>) ([Reactive] Implement retry() + TCK tests #1541)
• Single.switchIfEmpty(Single) ([Reactive] Implement switchIfEmpty + TCK tests #1527)
• Single.takeUntil(CompletionStage) decided not to have a dedicated operator for this
• Single.takeUntil(Publisher) ([Reactive] Implement takeUntil + TCK tests #1502)
• Single.timer() ([Reactive] Implement timer() + TCK tests #1516)
• Single.timeout() ([Reactive] Implement timeout() + TCK tests #1532)

[akarnokd]

Done.