Essex County said it will stop providing health insurance to its elected commissioners, a controversial perk that has cost taxpayers more than $730,000 over the past seven years. Though the commissioners largely have other full-time careers, 10 current and former board members accepted insurance coverage or payments for declining it since 2017, county documents obtained through a public records request show. They did so even as state law required all but one of those commissioners to work at least 35 hours a week to be eligible. But Adam Tucker, a spokesman for the nine-member board, said thos…