New Backend Support for curl requests

[tasiov]

Add support for curl requests as a web3 library

Looking to add support for curl requests as it is the next web3 library on the list.

curl requests are a command line utility that is not executed in the browser so some work will need to be done to transform curl requests to a browser friendly format like the browser Fetch API.

I propose an implementation that will look something like this:

In this implementation, curl requests are transformed to Fetch API requests, and both the curl and Fetch requests are displayed in the code sample. With the curl requests commented out, as it is not executed in the browser.

Clicking the "Send Request to Node" button will execute the Fetch API script and display results in the logs panel.

[abunsen]

Your JS code can use the fetch API, but IMO the code examples should use cURL.

[tasiov]

So the code examples should omit the fetch code? @abunsen