SPRINGFIELD — Advocates of universal healthcare will hold a rally on Tuesday evening at Baystate Health’s corporate offices to decry the Healey administration for its “inaction” on single-payer insurance, event organizers say. Rally organizers say they are in favor of state Senate and House bills that would establish Medicare for All, a single-payer health insurance program; that means a sole government payer. They claim Gov. Maura Healey has in…