By Devik Jain and Susan Mathew (Reuters) – U.S. stock indexes were set for a stronger open on Tuesday, led by gains in shares of megacap growth names and banks on signs of a de-escalation in tensions between Russia and Ukraine. Russia said some of its military units were returning to their bases after exercises near Ukraine and mocked repeated Western warnings about a looming invasion, but NATO said it had yet to see any sign of de-escalation on the ground. Megacap growth stocks including Apple Inc, Google-owner Alphabet Inc, Amazon.com Inc, Microsoft Corp, Meta Platforms Inc and Tesla Inc ros…