By Niklas Pollard and Simon Johnson STOCKHOLM (Reuters) -Swedish Prime Minister Magdalena Andersson will seek broad support for an application to join NATO on Monday, she announced on Sunday after her party dropped its long-standing opposition to membership in the wake of Russia’s invasion of Ukraine. Joining NATO was a distant prospect just months ago, but Russia’s attack on its neighbour has prompted both Sweden and Finland to rethink their security needs and seek safety in the military alliance they stood apart from during the Cold War. The war in Ukraine, which Moscow calls a special milit…