Pokémon page: Don't highlight non-damaging moves.

We highlight moves of the same type as the pokémon because they get
STAB. Don't do that for non-damaging moves.

Move pages already did this correctly, but change the code to match
the pokémon page, for consistency.
Pokémon flavor: Minor code cleanup

- Check pokemon_form_generations instead of introduced_in_version_id to
  decide whether to display each table of sprites.

  We already did this for Gen V (because of ??? Arceus and Spiky-eared
  Pichu).  Do it for the other generations for consistency.

  And because it reads nicely.

- Remove some unnecessary if statements.

  Gen V is over and it only has one set of sprites. We don't need to worry
  about which columns to show.
Pokémon flavor: Show X/Y sprites.

Shiny sprites too, even though we don't have them yet.