[TRI-1786] CLI dev command should have a flag for https

[matt-aitken]

For some webhooks like Instagram's, they require HTTPS. This can be achieved using an experimental Next.js feature in package.json:

    "dev": "next dev --experimental-https"

Our CLI dev command allows changing the hostname and port, and specifying a totally custom tunnel URL. But we don't allow enabled HTTPS.

Add -s --https flag.

_TRI-1786