WICKET-5243 JS: High stack size in Function Executor causes "too much recursion"

Execute the functions synchronously without allocation new stack frame (i.e. avoid recursion) when there is no need of such.
Only downloading of JS/CSS resources and execution of JS with manual control need to use the notify() call and recursion.
WICKET-5243 JS: High stack size in Function Executor causes "too much recursion"

Remove newly introduced test data and reuse the old one