It has been 49 weeks and five days since Jayson Tatum tore his right Achilles tendon against the New York Knicks, and he looks very much like himself on the floor . “It’s really been a long journey,” Tatum said after the Boston Celtics Game 1 win over the 76ers . “Obviously, a lot of things had to go right to even have the opportunity to come back and play, so obviously I thank God every day that I’m able to do and return to do what I love. From surgery the next day and Nick [Sang] and everything in between these last 48 weeks, it’s kind of been a buildup to today.” Tatum being back and mostly himself in the playoffs has changed the entire narrative around the Celtics. They had a great regular season without him, but with him looking as good as he has, they are considered the favorite to come out of the East.  And it’s that surgery the day after his injury that was so critical to Tatum’s amazing recovery .…