Fix escaping problem in write_literal and print_literal lint suggestion

[lapla-cogito]

fix #13959

The current implementation of the write_literal and print_literal lint performs escaping for the second argument of write! ,writeln!, print! and println! of the suggestion by first replacing " with \", and then replacing \ with \\. Performing these replacements in this order may lead to unnecessary backslashes being added if the original code contains " (e.g. " -> \\"), potentially resulting in a suggestion that causes the code to fail to compile.
In the issue mentioned above, it’s suggested to use raw strings as raw strings, but implementing this would require an ad-hoc change to the current implementation, so it has been deferred. (I'll implement this in another PR)

changelog: [write_literal]: fix incorrect escaping of suggestions
changelog: [print_literal]: fix incorrect escaping of suggestions

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[samueltardieu]

Maybe you could also include a \ in the tests as well.

[lapla-cogito]

Indeed, I've updated the test code.

[ChrisJefferson]

Just to say, this fixed my issue, and I tried poking it a bit more and couldn't break it.

I'd still like my raw strings leaving as raw strings in the long term (as I wrote them they way in purpose), but this definately fixes the issue of producing invalid code!