New signature for specifying error code

[mpyw]

// Currently supported
static mpyw\Exceper\Convert::to(string $class, callable $callback, int $types = E_ALL | E_STRICT): mixed
static mpyw\Exceper\Convert::to{$class}(callable $callback, int $types = E_ALL | E_STRICT): mixed

// Should be added
static mpyw\Exceper\Convert::to(string $class, int $code, callable $callback, int $types = E_ALL | E_STRICT): mixed
static mpyw\Exceper\Convert::to{$class}(int $code, callable $callback, int $types = E_ALL | E_STRICT): mixed

[mpyw]

it needs hard refactoring...