Proposal: Add lifecheck started status to pcp_watchdog_info.

Hi,
This patch adds a new field, "Lifecheck Started", to the pcp_watchdog_info output.
Currently, users need to inspect logs to verify whether the lifecheck has started on each node.
This change allows the status to be checked directly from a single command, making it easier to verify behavior and perform regression testing.
For example:

$ pcp_watchdog_info -h localhost -p 9898 -U pgpool -v
Password:
Watchdog Cluster Information
Total Nodes : 3
Remote Nodes : 2
Member Remote Nodes : 2
Alive Remote Nodes : 2
Nodes required for quorum: 2
Quorum state : QUORUM EXIST
Local node escalation : YES
Leader Node Name : server1:9999 Linux server1.localdomain
Leader Host Name : server1

Watchdog Node Information
Node Name : server1:9999 Linux server1.localdomain
Host Name : server1
Delegate IP : 192.168.56.150
Pgpool port : 9999
Watchdog port : 9000
Node priority : 1
Status : 4
Status Name : LEADER
Membership Status : MEMBER
Lifecheck Started : YES

Best regards,
Taiki Koshino<koshino(at)sraoss(dot)co(dot)jp>
SRA OSS K.K.
TEL: 03-5979-2701 FAX: 03-5979-2702
URL: https://www.sraoss.co.jp/