Add `wait()` method to Task class

[Strift]

Description

Add wait(int $timeoutInMs, int $intervalInMs) method to Task class.

Basic example

So instead of:

$task = $this->client->createIndex('new-index', ['primaryKey' => 'objectID']);
$task = $this->index->waitForTask($task->getTaskUid());

We could write:

$task = $this->client->createIndex('new-index', ['primaryKey' => 'objectID'])->wait();

[norkunas]

Added via https://github.com/meilisearch/meilisearch-php/pull/735/commits/aefc35dbc2b6db4c0a7bd3306a766ee080a0b176