LG-484 Display a message to the user when an account reset link is expired

[stevegsa]

Why: Currently when a link to delete account is expired the user has no indication that the link was expired after clicking on it. Moreover when there is a pending request for account reset and the token is expired, a cancel link still shows. The user can cancel and create a new request. However we should remove the cancel link when the token expires so that they can immediately create a new request.

How: Display a flash message to the user when the token is expired. When there is a pending request check for a valid token rather than the existence of a token.

Hi! Before submitting your PR for review, and/or before merging it, please
go through the following checklist:

• For DB changes, check for missing indexes, check to see if the changes
  affect other apps (such as the dashboard), make sure the DB columns in the
  various environments are properly populated, coordinate with devops, plan
  migrations in separate steps.

• For route changes, make sure GET requests don't change state or result in
  destructive behavior. GET requests should only result in information being
  read, not written.

• For encryption changes, make sure it is compatible with data that was
  encrypted with the old code.

• For secrets changes, make sure to update the S3 secrets bucket with the
  new configs in all environments.

• Do not disable Rubocop or Reek offenses unless you are absolutely sure
  they are false positives. If you're not sure how to fix the offense, please
  ask a teammate.

• When reading data, write tests for nil values, empty strings,
  and invalid formats.

• When calling redirect_to in a controller, use _url, not _path.

• When adding user data to the session, use the user_session helper
  instead of the session helper so the data does not persist beyond the user's
  session.

• When adding a new controller that requires the user to be fully
  authenticated, make sure to add before_action :confirm_two_factor_authenticated.

[stevegsa]

Screenshots:

After waiting 24 hours user gets notification with link to delete account

After clicking on the link >24 hours after they receive the email: (new)

If the user signs in >24 hours after receiving the email they no longer see a cancel link: (new)

[davemcorwin]

LGTM