enhance: add functions for daemon tools to do mTLS

[g-linville]

(The test failures on this PR are nothing new.)

This implementation is compatible with Express, which is what we use in our Node-based daemon tools. The app that Express creates is compatible with the listener argument that the createServer function takes.

Example usage:

import { createServer, startServer } from '@gptscript-ai/gptscript'

const server = createServer((req, res) => {
    res.writeHead(200)
    res.end('Howdy!')
})

try {
    startServer(server)
} catch (e) {
    console.log(e)
}