Include organization in vtctld progress targets

[nickvanw]

Summary

• add a shared vtctld target formatter that renders organization/database/branch in progress output
• update vtctld progress messages across workflows, keyspaces, materialize, move-tables, lookup-vindex, vdiff, and start/stop workflow commands
• add human-output tests that verify the org-qualified target is emitted in representative vtctld commands

Testing

• go test ./internal/cmd/branch/vtctld/...