CLI support for encoding/importing from JSON

[chenliu0831]

Things to check first

• [X] I have searched the existing issues and didn't find my feature already requested there

Feature description

Currently the CLI tool only supports converting CBOR data to representation that allows printing as JSON. The reverse serialization / importing is also a common task.

Happy to contribute as well.

Use case

It's convenient for manual testing with human readable JSON files/payload. Supported in this Rust project as well https://github.com/TakenPilot/cbor-cli.

Examples:

cbor2 -o test.cbor test.json --format=json

[chenliu0831]

@agronholm gentle ping, any thoughts on the feature and interface?

[agronholm]

I might be open to that, but would require a PR with tests, any necessary docs updates and a changelog entry.