Add Indexed positions to lists, allowing users to fetch n'th element

How: When working with Expression Lists, positions in the lists are not currently indexed. I want to be able to fetch the n'th value from a list (eg ["cat","dog","rhino"] - I want to fetch "dog" by accessing List[1], assuming the index starts at 0).

Why: Joining and splitting strings is useful to group/concatenate/splitting fields both on the same entity and across entities. Allowing users to access indexed positions, the user will be able to organize data to better fit export/API-needs.

For Who: Anyone using Expressions

Impact: Reduced complexity in integration-layers. Added control to the user.