By Andrea Shalal WASHINGTON (Reuters) – U.S. President Joe Biden will have a new “sherpa” on his trip to Germany next week – a former BlackRock strategist named Mike Pyle, who replaces Washington’s former point person on sanctions, Daleep Singh. Singh, who played a crucial role at the White House in coordinating Western sanctions against Russia over its invasion of Ukraine in February, this week took a job as chief global economist and head of macroeconomic research at PGIM Fixed Income, a Wall Street asset manager with $890 billion in assets. Singh, who was the deputy national security advise…