Feature request: loop and indexing, list manipulation

[yorgash]

For now ComfyUI does a great job at creating batches and lists.
The problem is we are usually either forced to work with all of them or none.
Adding a way to manipulate the lists, index them would be in my opinion essential.
A looping (even similar one to Easy-Use node pack's For... loop) would be most welcome as well.
I don't know about others, but I find myself more often than not using loops, with any number of manipulations, comparisons and transformations needed inside the loop.