By Sarah Marsh BERLIN (Reuters) -A regional election in Lower Saxony delivered mixed fortunes for German Chancellor Olaf Scholz’s national ruling coalition on Sunday, with his Social Democrats scoring a clear win but the Free Democrats barely on track to scrape into parliament. While the result signalled support for Scholz’s Social Democrats (SPD), some experts said the drubbing of its federal coalition partner risked destabilising Scholz’s administration at a critical time as Berlin strives to avert energy shortages and further escalation of the war in Ukraine. The other clear winner in Lower…