Introduced a new display message

[nmccann]

During testing integration with this library, we noticed that users were sometimes getting errors because they saw the "Passport read successfully" message (but not the checkmark) and then moved their phone away from the NFC chip, resulting in a read error.

It appears that this is due to the active authentication taking a bit of time to complete, and so it would seem useful to introduce messaging for this state before showing the "Passport read successfully" message.

An alternative approach would be:

• Keep successfulRead state change in it's current location, but change existing message to appear less "final"
• Add activeAuthentication state
• Add a new "final" state (name and message to be determined) to show after successfulRead and activeAuthentication have finished

[AndyQ]

Thanks - will add this in the next version

[AndyQ]

Merged - thanks