The `config dump` commands doesn't print default values

[alessio-perugini]

Describe the problem

We have received a PR in arduino/arduino-language-server#188 that wanted to address a nil pointer problem.
After a further investigation, we found out that the arduino-cli 1.0.0 introduced a regression.

The config dump only prints values present in the arduino-cli.yaml.

Here the diff: arduino/arduino-language-server#188 (comment)

To reproduce

arduino-cli config dump --json with the 1.0.0 release

Expected behavior

It should also print the default values for keys that are not present in the config file

Arduino CLI version

1.0.0

Operating system

Linux

Operating system version

23.10

Additional context

No response

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the nightly build
• My report contains all necessary details

[cmaglie]

This is the desired behavior, you can use config get .... if you need a specific value.

I've pushed a fix in the language server repo arduino/arduino-language-server#189

[per1234]

The regression point was at 1fddba7.

This should have been documented in the Upgrading doc at the time the significant breaking API change was made. I submitted a PR for that: #2676