Remove need for QUERY_ALL_PACKAGES

[Kaljurand]

The Google Play Support does not like the QUERY_ALL_PACKAGES permission and has blocked updates to the app in the Store. The need for this permission is described in:

https://github.com/Kaljurand/K6nele/blob/c325c6af425a4e8dc3e9ddb955aabe1fb829004e/app/src/main/AndroidManifest.xml#L43-L51

Possible solutions:

• ask Google Play Support (again) to reconsider
• build a reduced APK for Google Play without this permission, and recommend users to download from other app stores
• review the reasons why this permission is needed, and maybe drop some features if they are not essential (e.g. showing an icon next to a package name)