[OPR] Explain the open peer review process to the user when it is started.

After the reviewer has started the review, we should provide information that visually explains the entire review process as an overview.
This information must also be presented to the contributor after they have submitted data or after they pick up a review that has been conducted for one of their data sources.

In this way, we can ensure that it is understood that the process can last over a longer period of time and that several interactions between the reviewer and the contributor are necessary.

• create a visual overview of the opr (for reviewer and contributor pov)
• implement visualisation in oep and show it when either the reviewer or contributor collaborates on a reviewe (show it only once per review.
• In general, add helper text to any ui element if necessary