Spinner optimization

Signed-off-by: openmindead <openmindead@gmail.com>

Time for changes not related to spinner only...

Animation is shown during the boot-up, passphrase prompt moved down under the BGRT logo, vendor's logo is not hidden when the text field is shown.
Minor thing: centered vendor logo on the preview.

Rebase on the upstream

Another color accent for password entry field, end animation reversed.

Added preview

v1.1

Animated preview

Initial release

v1.0

First upload