DoubleEndedIterator implementation wrong #316
Description
It seems the double ended iterator is not behaving as expected.
It is important to note that both back and forth work on the same range, and do not cross: iteration is over when they meet in the middle.
https://doc.rust-lang.org/std/iter/trait.DoubleEndedIterator.html
There should be two pointers one pointing to the position at the beginning and one at the end.
The code moves the one pointer instead. Next back should move the later and keep the pointer used in next untouched.
https://github.com/davidcole1340/ext-php-rs/blob/8985cb2f82ac680083b74a5f377b2fda9c8f04d4/src/types/array.rs#L688-L728
If i have [1, 2, 3, 4, 5] - next() should return 1 and next_back() 5