Five-month-old Chaim Yehuda Shoham, the 19th American citizen killed in Palestinian terrorist attacks since the signing of the Oslo agreements almost eight years ago, was buried in Shilo last night. One of the thousands who took part in the four-hour funeral, which began outside the Prime Minister\'s office, was Sharon himself, who said emotionally that he accepts upon his shoulders the security of every boy and girl in this country. He asked permission to pay a condolence call to the family during the course of the week.