Add a method to delete the index only if it already exists

[curquiza]

Trying to delete an index that does not exist on the MeiliSearch server will throw an error. To delete it without any error no matter what if it exists or not, we need a new method.

• Add a method delete_index_if_exists: it deletes the index but does not throw any error if the index does not exist.
• Add tests

Example: https://github.com/meilisearch/meilisearch-python/pull/268/files

⚠️ This issue is generated, and delete_index_if_exists might be named differently in this package. Keep the already existing way of naming in this package to stay idomatic with the language and the repository.

Related to meilisearch/integration-guides#107

Sorry if this is already partially/completely implemented, feel free to let me know about the state of this issue.

[bofalke]

Hi, this sounds interesting, i would like to help out here

[alallema]

Hi @bofalke,
I can assigned you if you wish