Add `items` (or similar) element to Move endpoint

[DaltonSW]

The main thing I want is just some sort of additional information about a Move if it doesn't have any Learned By Pokemon. I wasn't familiar with some of these item-based Z Moves and was quite confused when I was getting Move results with 0 PP and no Learned By

There's already a machines element, so I think it would fit in, though it might need a bit of a different structure to get

[Manojshankar717]

Add items Element to Move Endpoint

Description

This PR adds an items element to the Move endpoint JSON response.
Now, when fetching a move, the response will include a list of items associated with that move.

Changes Made

• Updated pokemon_v2/moves.py (or the file where the Move endpoint is defined)
• Added logic to include items in the API response
• Added unit test test_move_items in tests/test_moves.py to verify the items element

Example Response

{
  "id": 1,
  "name": "pound",
  "type": "normal",
  "power": 40,
  "accuracy": 100,
  "items": ["quick-claw", "silver-powder"]
}

[phalt]

This PR adds an items element to the Move endpoint JSON response.

Which PR?