Add support for structured outputs in OpenAI-compatible completion

- Added `supportsStructuredOutputs` option to `OpenAICompatibleCompletionConfig` type
- Passed the option to `OpenAICompatibleCompletionLanguageModel` during creation
- Enables providers to specify support for structured outputs in completions

Author: michaelchiche

packages/openai-compatible/src/completion/openai-compatible-completion-language-model.ts

@@ -38,6 +38,7 @@ type OpenAICompatibleCompletionConfig = {
   url: (options: { modelId: string; path: string }) => string;
   fetch?: FetchFunction;
   errorStructure?: ProviderErrorStructure<any>;
+  supportsStructuredOutputs?: boolean;
 
   /**
    * The supported URLs for the model.

packages/openai-compatible/src/openai-compatible-provider.ts

@@ -133,6 +133,7 @@ export function createOpenAICompatible<
     new OpenAICompatibleCompletionLanguageModel(modelId, {
       ...getCommonModelConfig('completion'),
       includeUsage: options.includeUsage,
+      supportsStructuredOutputs: options.supportsStructuredOutputs,
     });
 
   const createEmbeddingModel = (modelId: EMBEDDING_MODEL_IDS) =>