Provides overall status for Precheck as well as actual NVDS to CVDS
upgrade status per host.
Precheck statuses are as follows
1. IN_PROGRESS: Precheck is in progress
2. FAILED: Precheck is failed, error can be found in precheck_issue field
3. PENDING_TOPOLOGY: Precheck is successful, recommended topology is generated
4. APPLYING_TOPOLOGY: SetTargetToplogy is in progress
5. APPLY_TOPOLOGY_FAILED: SetTargetTopology is failed
6. REDAY: SetTargetTopology is successful and TransportNodes provided as
part of topology are ready for upgrade from NVDS to CVDS