FORMAT field CICN and its relation to CN field

Reserved format field CICN was added in VCF v4.4 (vcf v4.4, 28-Jun-24) and yet to be added to 4.4 List of changes.
Also the relation between format field CI and format field CICN are not defined explicitly.

We can have something like, "CICN gives the confidence interval for CN field. CICN spans 0 with lower bound not greater than 0 and upper bound not lower than 0."
