Add a convenient way to toggle experimental features

[ellnix]

I was looking into implementing meilisearch/meilisearch-rails#316, but toggling an experimental feature currently requires a lot of smelly code.

Perhaps Client#set_experimental_feature!(feature, state)?

We already have tests on experimental features, and the test helper is currently the only place where we have a convenient way to toggle these features (and the implementation is not pretty): https://github.com/meilisearch/meilisearch-ruby/blob/main/spec/support/experimental_feature_helpers.rb

[curquiza]

We can indeed add this method in the SDK if you think this is convenient for the users
However, be careful this route is itself "breakable" -> fields can be accepted in some versions and not in another one if they are stabilized or removed

[ellnix]

I take most of what I said last night, I see that there's a standard way to do this in the reference: https://www.meilisearch.com/docs/reference/api/experimental_features

And we can get around the issue of missing options by simply polling Meilisearch for the available options, that way I won't have to hard code version numbers in meilisearch-rails in order to keep compatibility for multiple versions.

I'll go ahead and implement this in ruby since it seems to be already implemented in Go and Rust, unless there's a reason I shouldn't do it.

[curquiza]

You can go!