You can call Katie Couric the $10 million anchor. That’s how much Yahoo! CEO Marissa Mayer is forking over to retain the Web portal’s global news anchor, several sources told The Post on Friday. The new contract, agreed to in the last several days but not yet finalized, gives Couric a stratospheric annual pay package in line with that of NBC’s suspended Nightly News anchor Brian Williams.Only Couric is actually anchoring a newscast. The 58-year-old journalist, who had been negotiating a second contract for the past few months, won a significant rise. While the new deal contains a few...