Two issues:
- The UR2 sampler function was expecting the '1-3' indicator, and this is not included if there is a single UR fragment. Changed code to try to parse instead of relying on a complex regex.
- Fixed a similar issue with the UR1 sampler, but it can be simpler since we've already ruled out UR2.
- When sending the UR2 response, it always used "bytes" as the prefix. Now if it receives 'crypto-psbt', it responds with 'crypto-psbt'.
- Fixed is_ut_type() utility function which was incorrect
- All these fixes allow the code to work with BlueWallet's new UR2 support, but also stay compatible with older BlueWallet versions that only support UR1.
Ken Carpenter