Upgrading to 0.31.0

The org.occurrent.UpgradeToOccurrent_0_31 recipe rewrites the annotation ResumeBehavior and StartupMode enums into the shared top-level org.occurrent.annotation.ResumeBehavior and org.occurrent.annotation.StartupMode types, replacing the separate nested enums on @Subscription, @StreamSubscription and @DcbSubscription. It also updates the EventMetadata import, which moved from org.occurrent.dsl.subscription to org.occurrent.cloudevents. @Projection and @Snapshot are new in 0.31.0 and use the shared types from the start, so there is nothing to rewrite for them. See the upgrade guide for the details.