TSX ends up 156.99 points, or 0.8%, at 19,506.65 * For the week, the index advances 0.3% * Energy rises 4%; oil settles 2.7% higher * Materials group adds 0.8% By Fergal Smith TORONTO, Dec 23 (Reuters) - Canada's main stock index rose on Friday and posted a small weekly gain as higher oil prices bolstered energy shares, but worries that the economy was headed for a recession next year helped limit the...