refactor(client/index): expose wait_task on the client

[PLNech]

Exposes wait_task on clients, to avoid requiring an index reference for an operation that does not need it.

The end goal is to leverage it in algoliasearch_django, to avoid code like this:

    def test_delete_signal(self):
        Website.objects.create(name='Algolia', url='https://www.algolia.com')
        Website.objects.create(name='Google', url='https://www.google.com')
        Website.objects.create(name='Facebook', url='https://www.facebook.com')

        Website.objects.get(name='Algolia').delete()
        Website.objects.get(name='Facebook').delete()

        time.sleep(10)
        result = raw_search(Website)
        self.assertEqual(result['nbHits'], 1)
        self.assertEqual(result['hits'][0]['name'], 'Google')

[julienbourdeau]

In PHP, we use the path following path

'/1/indexes/'.$indexName.'/task/'.$taskID

It would be interesting to know if there is any difference between the 2 and which one is recommended.

[julienbourdeau]

It seems like we always need the index name to be able to test a taskID. This refactor was introduce with AB Tests (where having wait_task on the client came handy too).
Thanks PLN for the inputs 🙌

88f9b98

[iamr0b0tx]

see here maybe it can help