Merge EagerFutureStream and SimpleReactStream, remove time based operators from EagerFutureStream

[johnmcclean]

Eager Streams (EagerFutureStream and SimpleReactStream) perform a terminal operation on the underlying Stream at each phase, this means for any (more complex) operators (see list of operators that are batched for EagerFuturestream) that require data to flow though a queue they need to pull all data in from that Queue before the subsequent stages can be started (in other words data must flow through the queue to the next stage as a batch).

This makes time based operators such as batchByTime, jitter, debounce, chunked etc. less useful than for LazyFutureStreams. Reducing the operator set for EagerFutureStream would reduce the gap between it and SimpleReactStream - and perhaps they should be merged, leaving 2 streams

LazyFutureStream for infinite async streaming
and
EagerFutureStream, simpler API, for processing of small batches

[johnmcclean]

Keep separate, with better implementations for batchBySize, batchByTime, batchByTimeAndSize, debounce for EFS - v0.99 branch