fix: make sure to correctly initialize health checks (#17765)

health checks were missing for drives replaced since

- HealFormat() would replace the drives without a health check
- disconnected drives when they reconnect via connectEndpoint()
  the loop also loses health checks for local disks and merges
  these into a single code.
- other than this separate cleanUp, health check variables to avoid
  overloading them with similar requirements.
- also ensure that we compete via context selector for disk monitoring
  such that the canceled disks don't linger around longer waiting for
  the ticker to trigger.
- allow disabling active monitoring.

cmd/routers.go

@@ -85,7 +85,7 @@ func configureServerHandler(endpointServerPools EndpointServerPools) (http.Handl
 	// Add Admin router, all APIs are enabled in server mode.
 	registerAdminRouter(router, true)
 
-	// Add healthcheck router
+	// Add healthCheck router
 	registerHealthCheckRouter(router)
 
 	// Add server metrics router