Surface replay? on workflow contexts

[jeffschoner-stripe]

Adds a method to Temporal::Workflow::Context and Temporal::Testing::LocalWorkflowContext for determining if a replay is occurring. This makes it possible to write a replay-aware custom logger or metrics emitter for other logging libraries besides the built-in Ruby logger. Specs for LocalWorkflowContext are extended to cover this new method and a new specs file is added for testing Workflow::Context.

[robholland]

Suggested change

	@state_manager.replay?
	state_manager.replay?

[robholland]

Suggested change

	describe '#replay' do
	describe '#replay?' do

[robholland]

Missing newline before describe

[robholland]

My only slight concern would be that people might think they can safely use replay? for flow control. I understand your use case though and I'm not sure how else we'd satisfy it.

[jeffschoner-stripe]

After doing some more digging, I think we can get what we need without this change

• Inject our logger during configuration via Temporal.configure { |config| config.logger = foo } because its API is a superset of the logger gem's API
• Wrap this logger by formatting the messages within an adapter. This appears to be doable with a relatively small amount of code for our use case
• For metrics, there are already adapters and a null metrics object that should be able to allow for a switch-out pattern, but we'll have to figure out the details when addressing metrics