Add support for new generative-meta module

[antas-marcin]

This is a new module that will come out with latest v1.39.3 Weaviate version:

Here are the links to proto messages:

GenerativeMeta
GenerativeMetaMetadata

Available settings are:
baseURL - string (defaults to: https://api.meta.ai)
model - string (defaults to: muse-spark-1.2)
temperature - *float64
topP - *float64
maxTokens - *int
frequencyPenalty - *float64
presencePenalty - *float64
reasoningEffort - *string available values: "none", "minimal", "low", "medium", "high", "xhigh"