config: Add a display field

The display field is used to specify what needs to be displayed on the home page.

display:
  min-version: 'v2021'
  series-results:
    dailies: 4
    releases: 2
    weeklies: 3

That configuration will be used to only show results for v2021 and newer.

It will also limit the number of results for each series to be displayed. E.g.: For the releases,

• v2023pre+v2023dev3 (last 2 release results in the v2023 series)
• v2022.2+v2022.1
• v2021.6+v2021.5

The same principle will be applied to the dailies and weeklies.

An extra route is added to show all results by ignoring the configured display field.

The {{ url }} entries are dropped in the index template to make sure the link is not appended to "/all.html" on the "Show all" page.

The visual tests now have a display field added to the configuration.

This changes the index-page screenshot, where only the latest results are shown according to the configuration.

Also add a test for the "Show all" page, that actually shows the same page as index did before the display feature was added.

https://phabricator.apertis.org/T9232