Return default value when config value is not set

[milanholemans]

When I run cli config get --key prompt for example, and I haven't set any config value with this key, the command is just returning nothing.

In my opinion, this is not really a great user experience. It can be really confusing for users. When I encounter this, I have to look it up in the docs to find the default value for this config variable.

I suggest that when a config value is not found, we just return the default value.

---

On hold as long as the following issue is not resolved:

• Centralise default config values #6186