The From<String> for Message implementation has an interesting interaction between clap and how Message can be used from the command line.

Note that FromStr is not implemented for Message – which usually what is to be expected for use with clap, but in fact, clap also allows From<String>.

This would make Message be a required option when using rad issue comment.

It is not possible to use default_value_t because that required an implementation of Display, which in this case we do not want to implement. Trying to use default_value = "Message::Edit" also would not work – it uses that as the text.

So, the solution is to mark it as optional, and default to Message::Edit when it is not specified.

Rebase