Process service.yaml to identify latest API version and add it in release plan

Identify the latest API version when a release plan is created by parsing service.yaml to get the API versions and take the latest version.

Add API version in the release plan when it's created so it will be visible on the release plan dashboard. Dashboard already has the support to show API version as long as it is present in API-Spec ADO work item which is a child work item. DevOps service already handles this so change is to identify API version and pass it in release plan model passed to DevOps service.

For more info about service,yaml: https://github.com/Azure/azure-rest-api-specs/pull/44805