feat: Implement ngrok v1 proxy for serve command

[odanado]

Description

I implemented the integration with ngrok v1 as one of the integrations for the Tunnel feature.
This feature uses ngrok to tunnel the URL passed to the serve command, and sets the ngrok URL as the endpoint URL for the LIFF app.

Below is what the terminal looks like when the command is executed:

❯ npx @line/liff-cli serve -l 1234567890-aBcDeFg -u http://127.0.0.1:8081 --proxy-type ngrok-v1 --ngrok-command ngrok
Successfully updated endpoint url for LIFF ID: 1234567890-aBcDeFg.

→  LIFF URL:     https://liff.line.me/1234567890-aBcDeFg
→  Proxy server: https://abc123.ngrok.example.com/

In order for users to use this feature, they need to install node-pty.
node-pty is a large package.
ref: https://bundlephobia.com/package/[email protected]

Because not all users will use the ngrok v1 integration feature, I specified it in peerDependencies.

[CLAassistant]

All committers have signed the CLA.

[odanado]

ngrok v1 does not allow us to obtain connection information in a format that is easy for programs to handle, like JSON.
ref: inconshreveable/ngrok#86

Therefore, we need to use node-pty.