By Hyonhee Shin and Jack Kim SEOUL (Reuters) -Conservative South Korean opposition candidate Yoon Suk-yeol was elected president on Thursday in one of the most closely fought races in recent history which will shape Asia’s fourth-largest economy for the next five years. Yoon, 60, from the main opposition People Power Party, edged out the ruling Democratic Party’s Lee Jae-myung with 48.6% of the vote to 47.8%, with around 99.8% of the ballots counted as of 5:30 a.m. on Thursday (2030 GMT Wednesday). A formal announcement is expected to be made later on Thursday morning. Yoon said he would honou…