Also continued a bit on the MFA verification system.
Moved some MFA routes to public space using updated login service to get
the current user that is either logged in or last attempted login (With
correct creds).
- Removed all existing SCSS usage of primary color.
- Cut down custom styles injection to just be css vars.
- Reduced button styles so default button is primary.
- Updated button styles to lighten/brighten on hover & active states even
when a custom color is set.
- Removed unused scss color vars.
- Updated default BookStack blue to achieve better accessibility.
