If column in the x table is list unlist it if possible
      Source: R/0_unlist_if_possible.r
      unlist_if_possible.RdIf column in the x table is list unlist it if possible
Arguments
- x
- object 
- replace_zero_length_with
- Default is replace NULLs with NA_character_ because vector of just NA is a logical class 
- remove_empty_values
- remove NA, "", etc. from list elements. (see - standardize_omit_empty())