New user onboarding

[ilicfilip]

New user onboarding experience, per https://github.com/ProgressPlanner/progress-planner-pro/issues/177

[github-actions]

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[tacoverdo]

Step 1

Unchecked privacy policy

Current state

Design

While the checkbox is unchecked, the button should be grey.
Also, with the checkbox unchecked, clicking the greyed out button should give a notice about the requirement for the privacy policy. It currently doesn't.
The button is currently placed in the right column, while it should be right-aligned in the center column.

_Design of the notification when clicking the greyed out button_

Checked state privacy policy

Current state

Design

When the checkbox is active, it should be yellow instead of red.

Use 'real' Ravi instead of logo in the right column

Current state

Design

Clicking the X should trigger a warning screen

Current state

Design

When a user clicks the X in the top right, it should go to a separate screen asking for confirmation if they really want to close the onboarding wizard. This to prevent from users accidentally dropping out of the onboarding.