fix: use protojson for CLI output serialization

[odsod]

Summary

• Replace printJSON (which used encoding/json) with protojson.Format at each call site
• encoding/json serializes internal proto struct fields (XXX_raceDetectHookData, XXX_presence) instead of actual message data on edition 2023 opaque API protos
• Fixes way connect mercedes vehicle-services showing empty output instead of service status data

Test plan

• go build ./... passes
• go test ./... passes
• Verified vehicle-compatibility and vehicle-specification already used protojson.Format correctly