use yaml for parsing msg and srv values

[wjwwood]

This should be backwards compatible with the JSON style inputs. Also, these packages already needed yaml, so it's not a new dependency. It also makes using this feature on Windows easier since you don't have to so quote escaping in a lot of cases.

@Kukanani FYI you should be able to do ros2 topic pub /chatter std_msgs/String "data: Hello world" with this pr.

[mikaelarguedas]

I like that that will be closer to ros1 and less painful to write!
Tested locally (on linux) 👍

[dhood]

I am in favour of this because I was annoyed I couldn't copy-paste stuff from ROS 1

[wjwwood]

I changed the base to be master now that #15 is merged.

[wjwwood]

We still need to make a decision on whether or not this should get merged today. CI:

• Linux:
  • 
• Linux-aarch64:
  • 
• macOS:
  • 
• Windows:
  • 

[dirk-thomas]

Sounds good to me to merge as soon as CI has passed (though CI won't test for the changed behavior).

[wjwwood]

I tested the behavior manually. I'll go ahead an merge since we've got a few pending changes that must go in anyways.