[TypeScript][Node] support for overriding HTTP request headers

[silasbw]

PR checklist

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• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
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Description of the PR

This approach is inspired by the typescript-fetch implementation.

Fixes #9035

[silasbw]

cc @CodeNinjai and @wing328

I wanted to attach an example implementation that satisfies #9035. I realize this PR could be extended to provide more consistency with typescript-fetch by, for example, implementing qs overrides. I'm happy to help do that, or try a different approach for setting content-type.

[wing328]

@silasbw Thanks for tagging me but I'm no longer involved in this project. I hope others will be able to help you out. Good luck.

[silasbw]

@CodeNinjai are the right person to provide feedback on this? or could you tag the right person?

[silasbw]

fwiw, I added a similar change to openapi-generator: OpenAPITools/openapi-generator#1868

[silasbw]

@frantuma, I saw you had some commit activity recently :) any chance you can point me at the maintainers for this code so I can work with them on this change?

[HugoMario]

hello @silasbw thanks a lot for this PR. i think i'm going to take a time to port this to 3.0.x version. BTW any time you need help with a PR just let me know.

[silasbw]

Sounds good, thanks @HugoMario 👍