Add CONTINUE_AS_NEW_VERSIONING_BEHAVIOR_USE_RAMPING_VERSION

[THardy98]

What was changed

DWISOTT - adds UseRampingVersion as a CaN versioning option

Why?

support new versioning option

1. Part of Expose CONTINUE_AS_NEW_VERSIONING_BEHAVIOR_USE_RAMPING_VERSION in SDKs features#807

2. How was this tested:
   Added integration tests

3. Any docs updates needed?
   Maybe ?

[carlydf]

instead of f(workflow_id, ramp_percentage), should we say something along the lines of:

  // The Target Version is chosen with the default formula:
  //   if calcRampThreshold(workflow_id) <= ramp_percentage:
  //     target=ramping_version
  //   else:
  //     target=current_version

I feel like f(workflow_id, ramp_percentage) will invite lots of questions.
I am ok being transparent about this formula -- we won't change it by default after GA because that could cause workflows to "roll back" accidentally, even with same ramp percentage

[carlydf]

calcRampThreshold is the name of the server function we actually use, so people (or claude) can look it up if they're interested

[THardy98]

I'm going to remove it entirely, I don't think we need to leak server versioning internals here (I also don't anticipate people finding this particularly necessary)

[carlydf]

We define Ramping, Current, and Target version here fwiw https://docs.temporal.io/worker-versioning#versioning-definitions fwiw, so people can look those up there