[lustre/ui/otp] Support native paste.

[hayleigh-dot-dev]

Mobile users are commonly going to want to long-press on the OTP input and paste the value, we need to make sure that works as expected. Currently the input itself is visually hidden and so it's not possible to long-press on anything to pull up the native paste option.

Let's checkout what guilhermerodz/input-otp is doing and see if we can replicate that.

Edit: looks like native keyboard-based paste doesn't currently work on desktop either.