EngineDebugger.send_message() doesn't clarify what the data array should look like

**Your Godot version:**
4.7 (stable)

**Issue description:**
im trying to use EngineDebugger.send_message() in my code and i dont see anywhere how you're supposed to structure the data:array parameter. editor sends an error that just says " ERROR: Invalid message received" and when looking at the docs it never explains what the data array is supposed to look like.

**URL to the documentation page:**
https://docs.godotengine.org/en/stable/classes/class_enginedebugger.html#class-enginedebugger-method-send-message

Start with the linked EngineDebugger.send_message() documentation page and inspect the method description and nearby examples. Clarify the expected structure of the data array and the meaning of the "Invalid message received" error, then update the page so users can construct a valid message without relying on undocumented behavior.

Written by the indexing model from the issue text.