This removes the dependency on ``me.dm7.barcodescanner:zxing`` and replaces it
with our own QR code scanner implementation using CameraX and ZXing. The main
reason for this change is to hopefully get better compatibility with obscure
devices. The barcodescanner library we were previously using seems unmaintained,
while Google is apparently putting a lot of effort into CameraX.
ScannerActivity has been almost entirely rewritten, but the functionality is
exactly the same as before.
The main goals of this patch are to:
- Improve the exception handling in Aegis and the way we present errors messages
to the user when they occur.
- Write exception stack traces to the log in more places, so that the ADB logs
we ask for from our users when reporting bugs become more useful.
- Reduce the amount of times we throw a RuntimeException, particularly when an
Android Keystore operation fails.
Achieving the above goals ended up resulting in a very large refactor. The
intro and unlock flow of the app need to be retested entirely.
We decided on calling the state file the "vault" a while back. This patch makes
the naming consistent across the codebase. I left "DatabaseImporter" classes
alone, because I'm not sure what a better name for those would be.
