[v1.12.0] Add methods for the batches API

Following the changes related to Meilisearch v1.12.0 mega issue

Description

Add a feature introduced in Meilisearch v1.12.0: the batches API.

For more information refer to the docs:

• Batches API reference

For reference, here is how this works in JavaScript using meilisearch-js:

// Get all batches
const batches = await client.getBatches();
// Get one batch by ID
const batch = client.getBatch(BATCH_UID);

Tasks

• [ ] Add the relevant methods to get one batch and get all batches (in meilisearch-js, the equivalent methods are getBatch() and getBatches())
• [ ] ⚠️ Add integration tests ⚠️
• [ ] Update the code samples in .code-samples.meilisearch.yaml for the following keys, using the same examples as their curl counterpart:
  • [ ] Add example for get_batch_1
  • [ ] Add example for get_all_batches_1