fix: allow maximum 3 open-source apps while common apps are active

When common apps are active, users will see maximum 3 open-source apps by default. If users click on a filter, all open-source apps will be visible.

When common apps are disabled in the Settings, all open-source apps will be loaded and visible.

The logic for replacing common apps with their F-Droid counterparts is removed. Those apps will be visible as part of common apps.

Same goes for PWAs.