Readonly `NativeSelect` missing kb focus

[mimarz]

Reported by community in DM on Slack.

NativeSelect is not possible to focus using keyboard like our other forms components.

NativeSelect has a readonly prop which applies readonly-styling and disables the field because select does not support readonly .

This breaks content flow in form with keyboard when using it with other elements that are readonly.

We should investigate if we should mimic readonly state for our NativeSelect, looking at other libraries it seems to be a common thing to do.

Note:

• We are already mimicing readonly state for our Radio and Checkbox which does also not natively support readonly state.