Implement comprehensive multi-season handling for AnimeON and Mikai
controllers to properly display and navigate anime series with multiple
seasons.
For AnimeON:
- Fix season numbering to use actual season numbers instead of array indices
- Group seasons by SeasonNumber property with fallback to index-based numbering
- Update season selection links to use correct season identifiers
For Mikai:
- Add relation fetching to discover sequels, prequels, and related anime
- Implement season detail collection and ordering by release date
- Refactor voice building to support multiple seasons per voice actor
- Update season selection UI to display all available seasons
- Add MikaiRelation and MikaiRelationAnime models for API data handling
