[Task](ui): remove `success` icon

[franzheidl]

Currently, we have two versions of a filled checkmark icon: success and check circle. Both can be used invariably, and basically carry the same semantics, however success has a square background area, check circle has a round one:

success – to be removed:

use check circle instead:

We're seeing both in use, sometimes on the same view and in close proximity to each other, laying a cognitive load on the user to process how these mean the same but are not. Also, success with its square background area evokes associations with a checkbox ui element, adding more potential for confusion.

In order to remedy this situation, we have decided to sundown success, and replace it with check circle wherever it is being used.

In order to achieve this, we need to:

• remove the import: import Success from "@material-design-icons/svg/filled/check_box.svg"
• keep the success name and allow further using it, but return check circle instead
• test the fallback solution
• update the success Icon to describe the fallback solution

Acceptance Criteria

• the import of check_box.svg is removed
• the success icon can still be called, but will return check circle instead
• there is a test in place for check circle´ being returned when calling success`
• success remains unchanged
• storybook showcases the correct icon
• there is a comment in the code to describe why we have removed the square-ish check_box.svg/success icon
• there is a comment in storybook that describes why success and check circle return the same icon for each of these