Banners are based on (`control`|`variant`) of **desktop-de-19**.
We removed this functionality a while ago, although knowing that it had a negative effect on donations. We want to reintroduce it this year and test the effect of displaying the content in an overlay vs. linking to an external page (again). This will most probably be the scope of desktop-de-20, but should be easy to apply to banners on other platforms, too.
{F31454168, size=full}
**Acceptance Criteria**
* Clicking the link "Wohin geht meine Spende?" in banners opens an overlay.
* The content of the overlay resembles the content of the [use of funds](https://spenden.wikimedia.de/use-of-funds) page.
* The rest of the content is darkened while the overlay is displayed.
* The overlay uses a maximum width of 630px.
* The width of the overlay can be reduced to make this portable to other banners (i. e. mobile).
* Impressions of the overlay are logged by EventLogging.
**Notes**
* We have a data file in wmde/fundraising-frontend-content that is used to populate the content. Ideally, this is used in banners, too.