Rename string_as_numbers function

To make it more clear what this function does, I suggest renaming this function to something like `string_ascii_numbers_order` (although even this suggestion needs to be cleaned up).

Start by locating the string_as_numbers function and its usages in the d8s-strings repository. Choose and apply a clearer name based on the function's actual behavior, update every reference, and verify that the existing checks or tests still pass.

Written by the indexing model from the issue text.