fix(rulegen): handle join('\n') style test code

[EYHN]

1. Support join('\n')

I'm trying to run just new-rule no-unexpected-multiline, It found rulegen not support test code pieced together using array.json("\n"), like

{
  code: [
      "const x = aaaa<",
      "  test",
      ">/*",
      "test",
      "*/`foo`"
  ].join("\n")
}

I found this kind of code widely in the eslint codebase, so it will be great if we can support this.

2. remove extra ,

And I found when meet unsupported code, rulegen will generate an extra ,, so I added a filter at

https://github.com/web-infra-dev/oxc/blob/45cf5fc3da04be07e2293ad1a8dc77b8690f1e9f/tasks/rulegen/src/main.rs#L363

3. handle escape string

The escape / and trailing / in the javascript code will break rulegen. example: "\"abc\\\n(123)\""

I made the following changes:

- test_code.replace('\n', "\n\t\t\t")
+ test_code.replace('\n', "\n\t\t\t").replace('\\', "\\\\").replace('\"', "\\\"")

[CLAassistant]

All committers have signed the CLA.

[Boshen]

Oh nice! Thank you!