[vkalapov]

Description:

Adds dry-run support to the deploy workflow. When --dry-run is passed, the
deployment runs through the full planning phase but all CF Cloud Controller
write calls are intercepted by DryRunCloudControllerClient, which records
intended changes without applying them.

What changes:

• New DryRunCloudControllerClient wraps the real client and captures
  apps/services/routes that would be created, updated, or deleted.
• DryRunChangeSet collects those records and is stored as a process variable.
• DryRunResult model added to the API; Operation gains dryRunResult and
  outputs fields so callers can read the predicted changeset after the
  operation completes.
• --dry-run parameter wired into DeployMetadata and the BPMN deploy flows
  (deploy-app.bpmn, xs2-deploy.bpmn, process-batches-sequentially.bpmn).

Design choices:

• The dry-run client delegates every read call transparently and no-ops or
  records every write call, so the planning steps run unmodified.
• The changeset is accumulated as a process variable and published to the
  operation response at the end, keeping it out of the hot path.

Issue:

LMCROSSITXSADEPLOY-3716