Rename observeWhileInState to collectWhileInState

[sockeqwe]

Renaming observeWhileInState() to collectWhileInState to be more aligned with flow.collect { ... }

Another interesting question would be though if we should do the same with
storewide observe(flow). Should it be renamed to collect(flow) which is could be misleading since flow.collect {...} is the way to call it. An alternative option is to rename observe(flow) to collectWhileStateMachineRuns(flow) or something like that.