ML-193: add secondary parser, search, and API coverage tests
Add ~80 focused tests across 10 files covering:
- Record set search by name, description, contained record title, artist name
- Navigation events for records, artists, record sets, links, and view-all actions
- MusicBrainz.ReleaseGroup parser (artist credits, included RGs, release IDs, types)
- MusicBrainz.ReleaseSearchResult edge cases (missing RG, unknown formats)
- LastFm.Session XML edge cases (non-subscriber, missing nodes)
- MusicLibrary.HttpError default status-kind mapping
- Discogs.API.ErrorResponse fallback message and retry-delay behavior
- ArtistRefreshWikipediaData {:cancel, :no_english_wikipedia} worker path
- StatsComponents grouped on-this-day records and anniversary labels
Claudio Ortolina
ec6980eea0