By Raneen Sawafta, Fadi Shana and Nidal al-Mughrabi WEST BANK/GAZA/DOHA (Reuters) -Hamas said on Tuesday it had received and was studying a new proposal for a ceasefire and release of hostages in Gaza, presented by mediators after talks with Israel, in what appeared to be the most serious peace initiative for months. A senior Hamas official told Reuters the proposal involved a three-stage truce, during which the group would first release remaining civilians among hostages it captured on Oct. 7, then soldiers, and finally the bodies of hostages that were killed. The official, who spoke on condi…