[REFACTOR] Improve Workflow State Resource updates

[dbwiddis]

Is your feature request related to a problem?

Currently the Workflow State resource document is only additive, using a Painless script during provisioning to append to a list. This prevented iteratively updating it during deprovisioning, leading to open questions like #691.

Following #778 we will have the ability to update any individual element of the Workflow State which will bring these benefits:

• Allow for incremental addition to the resources created without using Painless, improving portability
• Allow for incremental removal from the resources created during deprovisioning, allowing the full deprovisioning to depend on this update. (See [FEATURE] Update WorkflowState resources during deprovisioning #780)
• Allow for the easy removal of the "error" field on subsequent successful provisioning

What solution would you like?

Replace the painless script with appropriate code from #778. Use ifSeqNo() and ifPrimaryTerm() on the update requests to enforce concurrency, and retry if it fails.

[dbwiddis]

Coming from #763 (comment), there's a lot of repetitive boilerplate used in Workflow Steps for exception handling during resource updates. As part of this refactoring, the "failed" update code should be de-duplicated.