[v1.19.0] Add sharding support

Context

We want to update the SDK to support Meilisearch 1.19 features.

Description

Meilisearch now supports sharding to enable horizontal scaling. Read the docs for more context on implementation.

The following changes in Meilisearch API need to be reflected in this SDK:

• Network API (first introduced in Meilisearch 1.13) now allows enabling sharding
• Network API responses now include writeApiKey in the remotes objects
• Tasks API responses now include remotes objects for tasks

Tasks

• [ ] Update the Network methods to accept sending the sharding parameter
• [ ] Update the Network methods to include remotes.[remoteName].writeApiKey in the responses
• [ ] Update the Tasks methods to include remotes objects in the tasks reponse index update method to allow renaming
• [ ] Add new test cases to test implementation