Encrypted drive auth screen: active state

[ninavizz]

Child issue w/in #910

This issue's punchlist

Zeplin, here
(note: this mockup uses screenshots w/ graphics added where things changed, so if you're confused why some text looks odd—well, that's why!)

• Implement active state spinner w/ button styling
• Disable Password field when actively submitting pane for auths
  • This includes "fading" the label for the text field, and the bullets or text in the field
• When returning an error'd screen, return the screen to its state w/o the error

[eloquence]

@ntoll Same here, also ready for ya :)

[ninavizz]

I made this GIF 3-4x as big as it needs to be, so it doesn't look sucky. Let me know if you need it to be a different size!