PERF: interpolate_1d returns function to apply columnwise
This doesn't provide a significant improvement for the existing asv due to the bulk of the time creating python sets which is in the function applied columnwise. see #34727

even without #34727 this could provide perf improvements for other index types ( and for unsorted indexes with creating a column-wise function for the numpy call.

will look at adding asvs for these cases.
I'll close this to clear the queue for now. Some deeper changes now planned so will reopen once complete.