By Stanley Widianto NUSA DUA, Indonesia (Reuters) -Russian Foreign Minister Sergei Lavrov will have his first close encounter with the fiercest critics of his country’s invasion of Ukraine at a G20 gathering in Indonesia that was getting under way on Thursday with the war all but certain to dominate discussions. A closed-door foreign minister’s meeting on Friday will be the first time Russian President Vladimir Putin’s top diplomat Lavrov will come face-to-face with the most vocal opponents of the invasion of Ukraine in February, which Moscow has called a “special military operation”. Lavrov p…