feat: Add Generation VII form-specific Pokédex flavor text

[MiquelRForgeFlow]

Adds English form-specific Pokédex flavor text to pokemon_form_flavor_text.csv for alternate forms as they appear in the Generation VII games (Sun/Moon, Ultra Sun/Ultra Moon) and Let's Go, Pikachu!/Eevee!.

244 new entries across 51 forms, structured per-pokemon so each can be reviewed independently (following up on the per-pokemon approach agreed in #1629):

• Alolan forms (18 forms, 108 entries) — regional variants of Kanto species.
• Mega Evolutions (32 forms, 110 entries)
• Oricorio (4 styles, 16 entries), Necrozma (Dusk/Dawn/Ultra, 6 entries), Basculin (both stripes, 4 entries).

Default-form flavor text already lives in pokemon_species_flavor_text.csv, so it is not repeated in this file. The only default-form entries included are cases where the default is a named variant within a form set and it would be odd to list the other members without it: Oricorio (Baile Style) and Basculin (Red-Striped) — like Deoxys (Normal Forme) from #1629.

AI coding assistance disclosure

Non-default forms have no canonical in-game line breaks in the veekun source nor in other sources, so they are reconstructed with a greedy word wrap. The wrap width was chosen to match the existing dataset's line-length distribution (median ~44, 95th percentile 50, max 54), which is consistent across SM, USUM and LGPE — LGPE uses the same text-box width as Sun/Moon, so a single width applies to all versions. Curly typography (' " ") matches the rest of the dataset.

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
• I have read and understood the AI Assisted Contribution guidelines.
• I will own this change in production, and I am prepared to fix any bugs caused by my code change.