Missing "removeUnleashEventListener" to the existing "addUnleashEventListener" #120
Description
Describe the feature request
In the old SDK one could registered and de-register such listeners.
In the new SDK, it looks like registering a listener starts a forever running coroutine which constantly looks at the flow it is interested in, and is only ever stopped when the job is cancelled job.cancel("Unleash received closed signal") when the entire client is closed.
Background
My use case is that during my app lifecycle, for various reasons, I sometimes want to observe the status of new flag updates coming in, and then I want to stop doing that without leaving jobs running on the background.
Solution suggestions
Add a pair removeUnleashEventListener function and make those listeners be able to be removed at will