`event.which` is deprecated which causes issues when using @testling-library/user-event v14

[kapiljaveri]

https://developer.mozilla.org/en-US/docs/Web/API/UIEvent/which

Issue found here - testing-library/user-event#1137

It's recommended to switch over to event.code or event.key instead - testing-library/user-event#842 (comment)

[kapiljaveri]

Probably looks like we also need to change - https://github.com/react-component/util/blob/master/src/KeyCode.ts