PARIS, Sept 5 (Reuters) - France will send gas to Germany if needed while Germany stands ready to provide it with electricity, President Emmanuel Macron said on Monday, saying this showcased European solidarity in the face of the energy crisis stemming from the war in Ukraine. European gas prices surged, share prices slid and the euro sank on Monday after Russia stopped pumping gas via a major supply route, in another warning to the 27-nation EU as it scrambled to respond to the crisis ahead of winter. "Germany needs our gas and we need power from the rest of Europe,...