SAN SALVADOR( Reuters)-El Salvador's vice president has delivered the final proposal for constitutional changes to President Nayib Bukele, including the extension of presidential terms and a new electoral tribunal body, the government said on Thursday. The president's legal adviser, Javier Argueta, said in an interview with a local television station that Bukele will review and study the proposals before sending them to Congress, where Bukele's party has a large majority.A team of lawyers led by