Use a diff writer instead of complete override for JSON editor config conversions

[JoshuaKGoldberg]

🚀 Feature Request

Forking from #742: editor configs can have a lot of formatting considerations in them that we won't want to override. Spacing, sorting, comments, trailing commas or lack thereof: these are all things that should be preserved when writing a new config.

Existing Behavior

We directly write the results of JSON.stringify()ing a new computed editor config.

Change Proposal

Use something like jsondiffpatch to write the new config.

Note: this issue will also apply to Atom's CSON configs (#728).

[KingDarBoja]

Oh yes, this is a edge case but seems that json with comments is getting popular on recent user development tools, I am up for it to use a better tool (library in this case) to handle a diff write to avoid complete override of editor config.

[JoshuaKGoldberg]

Hmm, jsondiffpatch looks like it deals only with the parsed objects, not the raw source file text... so it's likely another library would need to be used.

[JoshuaKGoldberg]

https://en.wikipedia.org/wiki/JSON_Patch looks like what we're looking for.

[JoshuaKGoldberg]

Hmm, that one works on document objects. Maybe it'd be easier to go with native TypeScript APIs, since that's already used for the file comment parsing... https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API