Feat: add identity (ORM-1261)

[niltonheck]

@micheleriva I would appreciate if you could double-check this implementation.

I tried to follow the current design but could eventually fail.

Task: ORM-1261 : [Client] Option to specify a custom unique ID

[linear]

ORM-1261 [Client] Option to specify a custom unique ID

As an Orama user, I want to integrate Orama on my website and define a custom unique ID, so that Orama can track data and connect multiple search sessions to the same known user.

(The provided id will be called alias_id and is provided to the Search client. It will be then saved in telemetry and answer engine data on Clickhouse, to later cross-reference and connect search/ai interaction sessions to a specific known user on the client's website)

Possible approaches (one, both, more?):

Option 1: call a dedicated method to identify a user as soon as their ID is known

import client from 'oramacloud/client'

// as soon as we have the unique user ID...
window.addEventListener('login-performed', e => {
  client.identify(e.my_user_id)
})

window.addEventListener('logout-performed', e => {
  client.clearSession()
})

Option 2: pass an option to Orama Client initialization

import { OramaClient } from 'oramacloud/client'

const client = new OramaClient({ 
  endpoint: 'https://cloud.orama.run/v1/indexes/videogames-ctw5x4', 
  api_key: '0YKaIrKohopObY7anjvFcR3XjEADNIyj',
  identify: () => `${session.user_id}`
})