Hive + HelathCheck: separate disconnects from restarts

[vporyadke]

Hive:

• Remember last local actor id even when killing (but not yet deleting) node
• Rename current restart statistics to disconnect statistics, keep using them for any "bad node" logic
• Add genuine restart statistics - ones that come with actor id change
• Add new field(s?) to node stats message

Healthcheck:

• Simply use the new fields