By David Gaffen NEW YORK (Reuters) -Oil prices edged higher on Thursday, maintaining their upward trajectory built on expectations that supply will tighten further even after OPEC+ producers stuck to planned moderate output increases. Tight global supplies and geopolitical tensions have boosted oil prices by about 15% so far this year. Demand remains on the upswing, with the Omicron coronavirus variation only temporarily denting consumption in major economies. The Organization of the Petroleum Exporting Countries and allies led by Russia, known as OPEC+, agreed to stick to monthly increases of…