Delete consumer group does not delete it unless the user clicks on Save

[Bachibouzouk]

On the demand view when the user deletes a consumer group, we should directly update the timeseries in DB (right now if the user quits the page and come back the deleted consumer pops back, only if the user clicks on save after delete is the consumer group deleted)

[paulapreuss]

i think this will stop being a problem when solving #72 so that the consumer groups are saved when clicking on a different ribbon. If we implement it to delete directly in the DB it will bring new problems since the dynamic elements like the graph work by hiding the traces instead of deleting them directly and they are dependent on the order/index of consumer groups not changing (unless the entire page is realoaded so that the graph is constructed from scratch)