Allow overriding Reranking options (provider, model, auth, parameters) on per-request basis for `findAndRerank` command

[tatu-at-datastax]

As per title, if reranking is enabled for a Collection, it should be possible to pass overrides to use (f.ex) different model for configured provider -- or even full provider/model override.

Notes:

• Override not allowed if Reranking Feature not enabled (for Data API instance)
• Override is allowed if Collection does not have it enabled
• Override definition must be complete (replacing Collection's definition, if any), not partial ("all or nothing") -- except that "auth" and "parameters" are optional
• Should make use of existing types where possible: for example CreateCollectionCommand.RerankServiceDesc for override definition