Add `split_components()` and `reduce()` methods to array type

[Zuzu-Typ]

split_components

split_components() is supposed to be a method that returns the various components of each element in multiple arrays.
For example, split_components() on an array that contains 3-component-vectors would return a tuple with three arrays. The first contains the X-values of each vector in the original array, the second the Y-values and the third the Z-values.
For matrices, split_components() would return column vectors for each column.
For number arrays, split_components() would throw an exception.

reduce

The reduce() method ist supposed to behave like functools.reduce.