ENT-11838: Fixed perpetual warnings that a deleted host has checked in

[larsewi]

• Added acknowledge field to lastseen DB
• Added acknowledge function for lastseen entries

[larsewi]

Lastseen migration seems to work after upgrading from nightly package to this PR :rocket:

# cf-check dump /var/cfengine/state/cf_lastseen.lmdb
{
	"a192.168.56.10": "SHA=b77ed17a94a734afb143610a28e4c81bcfe916866680390285f09c73dd7e7f9b",
	"kSHA=b77ed17a94a734afb143610a28e4c81bcfe916866680390285f09c73dd7e7f9b": "192.168.56.10",
	"qiSHA=b77ed17a94a734afb143610a28e4c81bcfe916866680390285f09c73dd7e7f9b": {"Q":{"dq":18.0000,"expect":-400760018451613696.0000,"q":159.0000,"var":2830478588096048211122947263693},"acknowledged":false,"lastseen":1728629014},
	"qoSHA=b77ed17a94a734afb143610a28e4c81bcfe916866680390285f09c73dd7e7f9b": {"Q":{"dq":18.0000,"expect":-400760018451613696.0000,"q":159.0000,"var":2830478588096048211122947263693},"acknowledged":false,"lastseen":1728629014},
}

[larsewi]

New field seems to do the job when built together with https://github.com/cfengine/nova/pull/2339

# cf-check dump /var/cfengine/state/cf_lastseen.lmdb
{
	"a172.31.36.65": "SHA=a624c8d1ee1edb763b5a901c5140fe96e9a495c1e3532aaee923da5754578bdc",
	"a172.31.38.8": "SHA=aa5231a2b12a6511f97baf2313901bcc73bed4a2ac76d7d52201f128f2dd43f4",
	"kSHA=a624c8d1ee1edb763b5a901c5140fe96e9a495c1e3532aaee923da5754578bdc": "172.31.36.65",
	"kSHA=aa5231a2b12a6511f97baf2313901bcc73bed4a2ac76d7d52201f128f2dd43f4": "172.31.38.8",
	"qiSHA=a624c8d1ee1edb763b5a901c5140fe96e9a495c1e3532aaee923da5754578bdc": {"Q":{"dq":0.0000,"expect":0.0000,"q":0.0000,"var":0.0000},"acknowledged":true,"lastseen":1728899299},
	"qiSHA=aa5231a2b12a6511f97baf2313901bcc73bed4a2ac76d7d52201f128f2dd43f4": {"Q":{"dq":277.0000,"expect":181.8218,"q":289.0000,"var":30371.9887},"acknowledged":false,"lastseen":1728899721},
	"qoSHA=a624c8d1ee1edb763b5a901c5140fe96e9a495c1e3532aaee923da5754578bdc": {"Q":{"dq":60.0000,"expect":24.0000,"q":60.0000,"var":1440.0000},"acknowledged":false,"lastseen":1728899360},
	"qoSHA=aa5231a2b12a6511f97baf2313901bcc73bed4a2ac76d7d52201f128f2dd43f4": {"Q":{"dq":277.0000,"expect":182.2317,"q":289.0000,"var":30164.9899},"acknowledged":false,"lastseen":1728899721},
}