Fix paste for personal key confirmation (IdV app)

[aduth]

Why: Because the primary user interaction we expect here is for the user to paste the personal key after clicking the "Copy" button on the personal key display page.

Testing Instructions:

1. Go to http://localhost:3000
2. Sign in
3. Go to http://localhost:3000/verify
4. Complete proofing flow up to personal key screen
5. Copy personal key
6. Click Continue
7. Paste personal key by some other means than Cmd + V, e.g. right-click or Mac "Edit" dropdown

Before: Content is not pasted
After: Content is pasted

Implementation Notes:

This may be a bug in Cleave.js, where after the input value is changed, it tries to format the value, and expects to use the last input value ([1][2]). This value is initially undefined and only set in response to keydown events, so if the user were to type regularly in the field, or use key combinations like Cmd + V, the value would be set ([3]). When directly pasting, it would be undefined, resulting in an error trying to slice an undefined value.

The resolution proposed here is to force Cleave.js to assign a string value for lastInputValue when initialized, via its internal updateValueState method ([4]).

Edit: Upstream report: nosir/cleave.js#691

[zachmargolis]

LGTM, love covering with a capybara spec too