[Runtime] switch batch schedule interface from STL to C array style

Using the STL iterator based approach has caused more harm than it
has advantages.

First of all it is unneeded we know how the Fibers we want to schedule are stored
and don't need a algorithmic generic abstraction.

We keep Fibers pointers in continues memory for memory locality benefits
therefore we can simply use the C dynamic array style of passing the
Fibers to the scheduler.

This removes the template from the batched schedule methods and allows us
to use virtual functions to specialize the batched scheduleFromAnywhere
method.