Tony Blair’s son Euan has appeared on a list of the richest Brits for the first time on the back of a hefty stake in his educational tech ‘unicorn’ Multiverse. Blair, 40, has seen his net worth swell to some £327m according to the Sunday Times Rich List, comfortably outstripping his father’s reported £47m. The younger Blair owes his wealth to a reported 25 per cent stake in the tech firm he co-founded in 2016 as Whitehat, which works with majo…