consistently capitalise List when referring to the spec data structure

[michaelficarra]

There's some places where we refer to a List as a "list".

- argumentsList is the list of arguments values passed to the method
+ argumentsList is the List of arguments values passed to the method

- and it would be unobservable if an implementation removed the pair from the [[TemplateMap]] list.
+ and it would be unobservable if an implementation removed the pair from the [[TemplateMap]] List.

- Initially a new empty List, representing the list of objects to be kept alive until the end of the current Job
+ Initially a new empty List, representing the objects to be kept alive until the end of the current Job

etc.