This function is ready to be moved. It just needs

• A review of its docs in and args to go in line with torch.linalg.
• Make torch.cholesky_solve an alias.

The only point left to discuss is: do we want to name it torch.linalg.cho_solve in line with scipy or do we want to maintain the cholesky_solve name? In my opinion our name is better, but perhaps it's better to change it for compatibility purposes?

cc @jianyuh @nikitaved @pearu @mruberry @heitorschueroff @walterddr @IvanYashchuk @xwang233 @lezcano