HUDSON COUNTY — The largest hospital group in Hudson County is expanding its insurance plans and uniting its three hospitals into one health system, company officials will announce today. The move, which follows a nationwide trend of consolidating healthcare services, is designed to transform Hudson Holdco from a small, single-county operator into a statewide player. By the end of the year, Holdco, which is rebranding itself as CarePoint Health, plans to offer a Medicaid insurance plan and be an option on the federal exchange — the marketplace that uninsured individuals can choose from when the Affordable Care Act takes effect in 2014.