Fix #12169 - Resample category data with timedelta index
closes #12169 

pls add a whatsnew entry as well.

Can you also add a simpler example (as well) that just hits the construction path; put it in the `series/test_constructors`
 @jreback added tests
 thanks @BranYang 

one tip, when you add a bug fix put it in a blank spot not at the end. that way you won't get merge conflicts (that's why I randomly put blank lines there)
