LONDON — “Across the country, the Conservatives are coming back,” declared a beaming opposition leader Kemi Badenoch earlier this month — after her party lost 801 council members in England, 19 seats in Scotland and 22 in Wales.  Behind her, the party faithful cheered as she bellowed “Conservative hold” rather than “Conservative win.” But the party that was running Britain less than two years ago is now so depleted that merely clinging on in loyal areas is now labeled as a victory. Since then,