builtins: pass arguments of RunAddon() to ActivateWindow() (fixes JSON-RPC's Addons.ExecuteAddon)

This makes sure to pass on any parameters provided in the call to the RunAddon() builtin function on to any resulting ActivateWindow() call and therefore to the plugin being executed. We already pass on the parameters for any non-media addons.

This fixes a bug reported in the forum when using JSON-RPC's Addons.ExecuteAddon on a video or music addon with specific parameters (e.g. to jump to a specific section of the youtube plugin).