Update target framework to 14 and test with latest Android versions

[volllly]

We need to investigate how changes regarding background service handling and file system permissions in newer android versions will affect us.

Tasks

• Update the target framework to Android 14
• Add an Android 14 test device to the App Center device set for smoke tests (https://appcenter.ms/orgs/fiskaltrust/apps/fiskaltrust.Launcher/test/device-sets)
• Check if the android launcher works on latest android versions 13 and 14
• Test with Fiskaly SCU on emulator using the middleware-demo-android
• Test with Swissbit SCU (@TSchmiedlechner can this be done on the emulator? - No)
• Document encountered problems in this issue

[pawelvds]

https://developer.android.com/about/versions/14/changes/schedule-exact-alarms

in Android 14 version requirements releated to alarm has changed, now we have to ask user for manual approval