Feature: export Requests to cURL commands

### Issues - [x] I have checked [existing issues](https://github.com/rest-nvim/rest.nvim/issues?q=is%3Aissue) and there are no existing ones with the same request. ### Feature description It would be great to have an option to export requests from a `.http` file to a cURL command format, similar to the functionality [provided by the intelij Idea HTTP client](https://www.jetbrains.com/help/idea/http-client-in-product-code-editor.html#http-to-curl). As many clients like Postman supports importing curl commands, this can allow converting `.http` files as collections for other clients with scripts, thus can be shared Would be cool if we can import curl commands as `.http` files too