SFDX Project configuration YML support

[dieffrei]

Is your feature request related to a problem? Please describe.
sfdx-project.json file becomes very difficult to read when it is big, currently, we already have +50 packages and for the next year probably it is going to be around +100.
Large text files lead to merge conflicts, also is very difficult to understand multi-directory projects.

What are you trying to do
I would like to have more flexibility on sfdx-project.json files. E.g: group packages per domain, provide them some capabilities like comments, or even have more granular configurations (per package).

Describe the solution you'd like
YML support E.g (sfdx-project.yml)

Additional context
Large sfdx-project.json files

[github-actions]

Thank you for filing this feature request. We appreciate your feedback and will review the feature at our next grooming or sprint planning session. We prioritize feature requests with more upvotes and comments.

[git2gus]

This issue has been linked to a new work item: W-12047419

[yippie]

To add to this, when there are lots of packages with dependencies, needing to specify the entire dependency tree for every package is very verbose and cumbersome. Supporting cascading dependencies would be super helpful.

[AllanOricil]

I've created a proposal for this issue.

#1915

Just copy (get inspired by) what maven did with pom files. Each package directory will have its own sfdx-package.json. The sfdx-project.json will behave as if it was an aggregator pom when working with maven projects.

This change will ease the implementation of a sfdx reactor (like mvn reactor)

#1950