Refactor: PINEnter Screen

[timbl-ont]

First stab at the requirements for the PINEnter refactoring - add others and provide feedback as required to this issue:

The PINEnter screen is used in multiple contexts that will need to be supported as part of the refactor:

• User Authentication at wallet initialization
• Enhanced or use case specific authentication
  • Change Biometrics
  • Change PIN
  • Proof of presence (future)
  • Other higher risk settings changes (TBD)
• PIN reminder (future) - user is asked to enter the PIN when they are using biometrics to remind them of what there PIN is. The Signal app does this fairly well.
• Wallet unlock after idle timeout
• ???

In addition the user lockout behaviour on an incorrect PIN entry will change depending on the context. There are two paths:

• Lock the user out of the wallet for a period of time after n failed attempts. The period of time should increase by x amount every n failures (with some max limit). All variables must be configurable and injectable. Used for wallet authentication flows.

• Lock the user out of the specific PIN Enter context for period of time after n failed attempts. For example if the user fails to change their PIN then they would be locked out of only the PIN change functionality and not the entire wallet. The period of time should increase by x amount every n failures (with some max limit). All variables must be configurable and injectable. Used for enhanced authentication and PIN reminder. Variables may be different for each context???