refactor: Change focus and validation behavior of password inputs

[maiertech]

Description of change

Route /welcome/password:

1. The password input element gets initial focus.
2. The password input element gets the focus back when toggling password visibility.

Route /welcome/password/confirm:

1. The password input element gets initial focus.
2. The validation triggers only when the passwords match or when the input element loses focus.
3. The password input element gets the focus back when toggling password visibility.

Links to any relevant issues

Fixes #222.

How the change has been tested

Manual visual testing. Reset the app in dev mode and walk through the onboarding process. Toggle visibility and make the input element lose focus.

Definition of Done checklist

Add an x to the boxes that are relevant to your changes.

• [x] I have followed the contribution guidelines for this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[SoulaAndrikopoulos]

From a usability perspective: As we discussed earlier it would be nice to still have an indicator when the passwords don't match, just not immediately at the beginning when the user starts typing :) Otherwise not a lot to add to the other comments.