Refactor pad handles (#4386)

* Set up [userid, type, index] -> pad_handle mapping and hook up currently existing GameControllers backend to it

* just use basic oop principles why are we even shoving callee responsibility in caller logic

* support special pads

* random edge case I thought of

* return error if handle is already opened, redirect scePadOpenExt to scePadOpen

* scePadClose

* error out if trying to close an unopened handle

* oof

* logging