• Prevents FIFO.DequeueOrWaitForNextElement to keep waiting for a waitChan while internal queue contains items

• Prevents FIFO.DequeueOrWaitForNextElement to add useless wait channels

Prevents FIFO.DequeueOrWaitForNextElement to gets blocked when waiting for an enqueued element.

FixedFifo.Enqueue prevents to gets blocked trying to send the item over an invalid waitForNextElementChan channel

• Added DequeueOrWaitForNextElementContext(...) both for FIFO and FixedFIFO
• Updated tests:

  FixedFIFO.TestDequeueOrWaitForNextElementMultiGR
  FixedFIFO.TestDequeueOrWaitForNextElementWithEmptyQueue

Added DequeueOrWaitForNextElement() both for FIFO and FixedFIFO

First In First Out (FIFO) concurrent queue