By Lucia Mutikani WASHINGTON (Reuters) -U.S. wholesale inventories increased solidly in March and the pace of accumulation in the prior month was stronger than previously reported, which could lead to a small upward revision to the first-quarter gross domestic product estimate. The Commerce Department said on Monday that wholesale inventories rose 2.3% in March as reported last month. Data for February was revised higher to show stocks at wholesalers climbing 2.8% instead of the previously reported 2.6%. Economists polled by Reuters had expected March inventories would be unrevised. Wholesale …