Tool: Implement packages list tree to json output using meteor list --json flag

[jankapunkt]

Currently I am writing a GitHub action, that resolves the current packages tree that results from the meteor list --tree command and checks for outdated package versions. However, this involves manually parsing the |-- symbols from the output to re-create the structure as a data model.

It would be much easier (and less error-prone) for this (and potential other actions / ci) to generate the packages tree directly as json file. From what I perceive,there would be the following changes

• add a json flag to the options
• implement a variable output target symbol that uses json syntax elements, if the --json flag is active.
• Otherwise, if --json is omitted, keep the actual output symbols for --tree
• If --tree is not active, --json is irgnored

I would myself start a PR,if this would get a green light

[filipenevola]

@jankapunkt 🟢

[jankapunkt]

PR opened at https://github.com/meteor/meteor/pull/11165

[filipenevola]

Merged. It will be available on Meteor 1.12