chore: Update LLM formatter classes to include additional details (#11491)

This PR introduces support for optionally exposing more data during LLM
function calls. This will be useful as we expand Copilot’s capabilities.

Changes included:
- Add support for ArticleLlmFormatter
- Add missing specs for ContactLLMFormatter and ArticleLLMFormatter
- Add additional spec for ConversationLLMFormatter based on config

app/services/llm_formatter/default_llm_formatter.rb

@@ -3,7 +3,7 @@ class LlmFormatter::DefaultLlmFormatter
     @record = record
   end
 
-  def format
+  def format(*)
     # override this
   end
 end