By Maya Gebeily, Timour Azhari and Tom Perry BEIRUT (Reuters) – In their move to bury an investigation into the Beirut port blast, Lebanon’s ruling elite have driven another nail in the coffin of the collapsing state, stirring conflict in the judiciary as they try to avoid accountability at any cost. Long-simmering tensions over the investigation have boiled over since Judge Tarek Bitar brought charges against some of the most influential people in the land, defying political pressure as he resumed his inquiry. With friends and allies of Lebanon’s most powerful factions, including Hezbollah, a…