typeIn helper forces maximum length check

When working with date / time inputs, it's sometimes desired behaviour to allow a user to keep typing beyond the `maxlength` attribute, for example wrapping a time or date input.

When upgrading to test helpers recently we've seen a lot of failing tests because a new check has been added to the `typeIn` helper. Whilst it seem well-intentioned, not providing a way to opt out of this behaviour adds a limitation that isn't necessarily what is desired.

Could I add a flag to opt out of maxlength checking?