feat: run prettier on migratedJSON

[RahulGautamSingh]

Changes

• add readLocalPath function to get local path of file from localDir
• run prettier using user's default setting on migratedJSON

Context

• Config migration: run prettier #16402

Documentation (please check one with an [x])

• I have updated the documentation, or
• No documentation update is required

How I've tested my work (please tick one)

I have verified these changes via:

• Code inspection only, or
• Newly added/modified unit tests, or
• No unit tests but ran on a real repository, or
• Both unit tests + ran on a real repository

[rarkins]

Please perform extensive testing once we reach a final version

[RahulGautamSingh]

Tested for these cases:-
No_indent defaults to 2 spaces
: https://github.com/RahulGautamSingh-testing/migrate_no_indentation/

uses same indentation ie. detected amount, tabs & spaces:
https://github.com/RahulGautamSingh-testing/tabs_present/
https://github.com/RahulGautamSingh-testing/spaces-3/

random_formatting defaults to 2 spaces and works for json5 :
https://github.com/RahulGautamSingh-testing/random_formatting

[viceice]

I've not checked the samples, so @rarkins merge when you're confident.

[renovate-release]

🎉 This PR is included in version 32.114.0 🎉

The release is available on:

• GitHub release
• 32.114.0

Your semantic-release bot 📦🚀

[viceice]

@RahulGautamSingh Please don't forget to add fixes or closes keywords to automatically close related issues 😉