Sentinel Client: Add connect/ready/end events

[BrianMwit]

Motivation

Redis Client (createClient) currently emits connect, ready, and end events as per documentation

const { createClient } = require('@redis/client');
(async () => {
    const client = await createClient({ name: 'myCache', url: 'redis://10.1.2.3:12345' })
        .on('connect', () => console.log('Redis connected'))
        .on('ready', () => console.log('Redis ready'))
        .on('end', () => console.log('Redis disconnected'))
        .on('error', err => console.error('Redis Error', err))
        .on('reconnecting', () => console.log('Redis reconnecting'))
        .connect();
    
    console.log(`client.isOpen: ${client.isOpen}, client.isReady: ${client.isReady}`);
    console.log('Get testKey', await client.get('testKey'));
    client.close();
})()

Results in

Redis connected
Redis ready
client.isOpen: true, client.isReady: true
Get test key null
Redis disconnected

However, Sentinel currently does not emit any of those events

const { createSentinel } = require('@redis/client');
(async () => {
    const client = await createSentinel({ name: 'myCache', sentinelRootNodes: [{ host: '10.1.2.3', port: 26379 }]})
        .on('connect', .... [same as above]

Results in

client.isOpen: true, client.isReady: true
Get test key null

Only error seems to be emitted.

I understand that "connect" and "ready" status for Sentinel might be ambiguous - is it connected to the Sentinel? and/or the node? But Sentinel itself also have isOpen and isReady properties. At least, the events can track these properties.

Motivation: Application using this library can handle startup, error, and reconnect events easier

Basic Code Example