automatic time-skipping (don't merge)

[feiyang3cat]

What changed?
new feature: automatic time-skipping configuration and new event type added

Breaking changes
new event type added but right now no workflow history will have this new event type

Server PR
not expect to break server, no new rpc-handler and new fields are all optional

[feiyang3cat]

@Sushisource Hey! I've cleaned this pr and ready for review.

And this config may need special attention since it is changed significantly from previous version Chad proposed.
(1)deleted most of the fine-grained control (like max timer-firing count, max duration to skip) from the previous version. The reason is it is ambiguous when complicated configuration is propagated to child-workflows.
(2) I have also changed the nested config to one single layer because this configuration is only used for automatic time-skipping, manual time-skipping will have a separate request and response payload
(3) we allow disabling time-skipping for in-flight workflows since it is not hard for the server to have this feature, and it will be a nice-to-have feature same as the SDK TestServer.

I think we can consider wrapping up this pr early, and put manual time-skipping in a separate pr maybe.
Pls feel free to disagree, happy to refine.

[Sushisource]

I think this looks totally reasonable - but I also don't see any reason to rush the PR while work is in progress unless we intend to ship a version without manual skipping first. If we don't, let's use the opportunity to develop it and decide if we want to make any changes to this config that relate to manual timeskipping.

[Sushisource]

I think this looks totally reasonable - but I also don't see any reason to rush the PR while work is in progress unless we intend to ship a version without manual skipping first. If we don't, let's use the opportunity to develop it and decide if we want to make any changes to this config that relate to manual timeskipping.