text: Title: [ENH]: Allow list of padding values for bar_label
  Body: ### Problem
  
  Sometimes when adding labels to bar plots the labels will overlap another item and need padding. In this example the label "300" (column D) is too low and overlaps other text. Ideally I could just provide padding as a list to `bar_label` so that I can target this specific label (instead of the current all-or-nothing float value):
  ![Image](https://github.com/user-attachments/assets/2fe80971-ba74-4e26-b2e4-b7a273c2efb9)
  
  With manually added labels I can add padding to just the desired label, but it would be nice as a built-in option:
  ![Image](https://github.com/user-attachments/assets/95a07b34-2a18-4ed6-98c4-107fd93de58a)
  
  ### Proposed solution
  
  Add logic to check if the `padding` parameter of `bar_label` is an appropriate-length iterable and apply padding accordingly.