gz topic -p publishes an empty message even when the input message to publish is invalid

[azeey]

Environment

• OS Version: Ubuntu 22.04
• Source or binary build? gz-transport3, 184c3df

Description

• Expected behavior: When the input message provided to gz topic -p is invalid, it should print an error and quit.
• Actual behavior: It prints an error and actually publishes an empty message.

Steps to reproduce

1. In one terminal, run gz topic -e --json-output -t chatter
2. In another, run gz toic -t chatter -m gz.msgs.Double -p "0.5"

The first terminal should print {} indicating an empty message was received[

[mjcarroll]

gazebosim/gz-msgs#384

[azeey]

Thanks @mjcarroll!