Scaling tool to improve LP matrix

[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.

Exclusion of unrelated changes, e.g., recursive dynamics and learning commits, are also required before integration with IIASA's main branch.

How to review

• Please check out this branch and try to work with this tool
• Write comment 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.

[glatterf42]

Thanks for this PR, @ywpratama :)
One thing to note right away: please keep the existing file structure intact. We want all tutorials to be available under tutorial/wherever they belong, so please add your tutorial there, too, instead of in some random location.