Palladium slumps nearly 13%, gold up to 4.6% as precious metals join virus-led free fall * Palladium facing its worst daily performance since 2008 * Palladium sheds about $390 from Thursday’s record high * Platinum on track for worst week since 2008 * Silver set for its biggest weekly decline since 2011 Feb 28 (Reuters) – Palladium led a free fall in precious metals on Friday, slumping nearly 13% at one point earlier in the session, while gold slid as…