[v1.9] Accept `distinct` search parameter

[curquiza]

Following this central issue

This is related to a newly introduced feature in Meilisearch v1.9.0: use distinct search parameter.

Refer to docs for more information.

• [x] Ensure the library can accept the distinct search parameter.
• [x] Add integration tests
• [ ] Update the .code-samples.meilisearch.yaml
  • [ ] Add search_parameter_reference_distinct_1 key and “translate” the following curl example by using the newly added methods: https://github.com/meilisearch/documentation/blob/04f26a35771305378ed0a506f4d60ef06d07bd7e/.code-samples.meilisearch.yaml#L1308
  • [x] Add distinct_attribute_guide_filterable_1 key and “translate” the following curl example by using the newly added methods: https://github.com/meilisearch/documentation/blob/04f26a35771305378ed0a506f4d60ef06d07bd7e/.code-samples.meilisearch.yaml#L1316C1-L1316C38
  • [x] Add distinct_attribute_guide_distinct_parameter_1 key and “translate” the following curl example by using the newly added methods: https://github.com/meilisearch/documentation/blob/04f26a35771305378ed0a506f4d60ef06d07bd7e/.code-samples.meilisearch.yaml#L1325

[curquiza]

Missing search_parameter_reference_distinct_1 in #1005

[curquiza]

@aweidner

Note that the issue mentions adding the code sample for distinct_attribute but it looks like this code sample is already in place according to the docs: https://www.meilisearch.com/docs/learn/relevancy/distinct_attribute#setting-a-distinct-attribute-during-configuration. Happy to amend this PR if that's not the case and I'm misreading this.

The missing code sample is used here: https://www.meilisearch.com/docs/reference/api/search#distinct-attributes-at-search-time

And of course thank you for your previous PR @aweidner 🙏 ❤️