Scaling tool to improve LP matrix (cleaned)

[ywpratama]

This branch contains the files and MESSAGE model updates to allow the model to run with an improved LP matrix. A tutorial is provided in message_ix/tools/make_scaler directory, but the text still needs some edits to improve clarity.

A test is being prepared for the pull request.

This pull request draft is currently built on top of ssp_dev.

How to review

• Please check out this branch and try to work with this tool
• Write comments to report any bugs or improvement suggestions

PR checklist

• [ ] Continuous integration checks all ✅
• [ ] Add or expand tests; coverage checks both ✅
• [ ] Add, expand, or update documentation.
• [ ] Update release notes.