Replace arguments shown in the JavaScript code blocks by "instanceContainer"

[4ian]

A JavaScript code block has by default "runtimeScene" as the first argument, then an optional "objects", then eventsFunctionContext.
In practice, this "runtimeScene" is NOT the runtime scene for objects and behaviors. Instead, it's the instance container.

We should probably not encourage using runtimeScene inside a function of a behavior and object. Instead, we could:

• keep runtimeScene for JS functions in scene events
• keep only eventsFunctionContext for JS functions in scene events and expose getInstancesContainer() on eventsFunctionsContext. Make an invisible const runtimeScene = this._instanceContainer.getScene() to keep compatibility.
• (bonus not linked to JS functions) Rework code generation to use eventsFunctionsContext.getInstancesContainer() instead of runtimeScene?
  • If we search "runtimeScene" in all .cpp/.h files, usage is already fairly low.