Deprecate FluxSink, MonoSink and SynchronousSink currentContext() method, add getContextView() one #2971
Description
It seems these three classes were overlooked when ContextView was introduced and the Context-returning methods were deprecated.
These three classes should get a ContextView getContextView() method, similar to what's been added to eg. Signal.
In addition, their currentContext() method should be deprecated for removal in 3.6.0 at the earliest.
The deprecation can occur either in 3.4.17+ or alternatively directly in 3.5.0.