ci(typescript): transformer

[ShaMan123]

closes #7839
#7596

Introduces a transformer that is able to transform most of the files under src into es6 and a few more perks.

• scripts/transform_files.js - the transformer logic
• scripts/index.js - expose cmd for cli (npm run dev transform -- --help)
• npm run dev transform -- --help to run the transformer (it will fail for transformed files - revert them beforehand if needed)

Take a look at 04be3f5 for outputs.
And I saw something very exciting in VSCODE:

group.class.ts.-.fabric.js.-.Visual.Studio.Code.2022-06-12.00-25-29.mp4

Then human work can be much easier:

• static properties
• imports/export/build/
• sub/super/abstract class
• cleanup (e.g. remove chainables)
• types
• private/protected - can be done with the transformer
• things missed out by the transformer (see dump.txt)

Transforming PRs is now possible!
I have tested the following:

• mock merging a PR into master (merged deprecate-extend into test-pr-transform)
• ran npm run dev transform -- -ts -o --diff
• committed changes 0b6da98
• merged branch into mocked transformed master 656bc9d (merged test-pr-transform into ts-proto)
• resolved conflicts

The conflicts were simple and weren't affected by the conversion.

[ShaMan123]

Ready to merge.
The src file changes are minor stuff that interfere with the transformer