Add all three GNU Taler apps
- The app complies with the inclusion criteria
- The original app author has been notified (and supports the inclusion)
- All related fdroiddata and RFP issues have been referenced in this merge request
- The upstream app source code repo contains the app metadata (summary/description/images/changelog/etc) in a Fastlane or Triple-T folder structure
- Releases are tagged
This MR adds three GNU Taler apps, each in its own commit.