New validation warnings

[FinnRG]

Part of #1450. Validation warnings are a good way to prevent common editing errors. We should add new warnings and update outdated/unspecific warnings. This is especially important for events and tags, where we don't have any warnings.

Current issues regarding validation warnings:

• 1325

• 1351

• 1362

• 1368

• 1369

Here are all of our current validation errors:

Songs

• DuplicateArtist: The same artist cannot be added twice. Please remove the duplicate and edit the roles accordingly
• NeedArtist: Song needs at least one artist.
• NeedOriginal: Derived songs need to have an original version specified, if it's in the database, or the original needs to be mentioned in notes.
• NeedProducer: Song should have at least one producer (composer, arranger or animator) role.
• NeedReferences: Song needs notes, PVs or links for reference.
• NeedType: Song type needs to be specified.
• NonInstrumentalSongNeedsVocalists: This song has no vocalists. Original instrumental songs need to be tagged with the 'instrumental' tag. Instrumental (karaoke) versions of existing songs should use the 'Instrumental' song type. Otherwise, add vocalists.
• RedundantEvent: The same release event does not need to be specified for both the song and album.
• RedundantRoles: Producer's roles do not need to be specified when that producer is the only one.
• UnspecifiedNames: Song needs a primary name.

Artists

• NeedReferences: Artist needs a description OR at least one external link as a reference.
• NeedType: Artist type needs to be specified.
• UnnecessaryPName: There is no need to add artist name both with and without the P suffix.
• UnspecifiedNames: Artist needs a primary name.

Albums

• DuplicateArtist: The same artist cannot be added twice. Please remove the duplicate and edit the roles accordingly.
• NeedArtist: Album needs at least one artist.
• NeedCover: Album needs a cover.
• NeedReferences: Album needs a description or links for reference.
• NeedReleaseYear: Release year needs to be specified.
• NeedTracks: Album needs a tracklist.
• NeedType: Record type needs to be specified.
• UnspecifiedNames: Album needs a primary name.

[Shiroizu]

The current warning coverage is pretty extensive. There are a couple common edit mistakes that could be added as new validation warnings that I could think of:

Song length: PV lengths should match for the same song entry (withing 5s or so). There might me rare edge cases to this.

Ambiguous producer roles: When song entry includes multiple producers (composer/arranger/voice manipulator), and if for one of them the role is specified, the roles should be specified for all of them. All producer roles should be either on default (= not specified) or specified for all of them.

• Example where this issue was fixed: https://vocadb.net/Song/ViewVersion/1596757?comparedVersionId=1596485

• "Osamu (Voice manipulator), Yunosuke" becomes "Osamu (Voice manipulator), Yunosuke (Composer)"

[Shiroizu]

Album entries do no seem to warn about missing voice synths. I think that could be added too.

[FinnRG]

@Shiroizu What about tag and event entries? I don't think new users usually edit them, but maybe there are some common editing mistakes that I don't know of. There was also some discussion about restricting tag editing to trusted+ users, to prevent mistakes. Maybe entry warnings could help with that (I don't want to restrict standard users to much, because TouhouDb and UtaiteDb don't have large trusted user groups).

[FinnRG]

Mentioned by @andreoda on discord:

1. New validation warning for venues in China.
2. new validation warning for missing publish dates on songs

[saturclay]

For the NonInstrumentalSongNeedsVocalists warning, I noticed (at least on TouhouDB) that this triggers even if you already tagged the song as instrumental--I'm not sure if that's a check that can easily be added, but I did find it confusing at first given that the warning explicitly says the tag is needed. Additionally, this warning doesn't really seem as applicable to TouhouDB, since, unlike VocaDB, there's not any particular reason why songs would need to have vocalists. Could/should this warning be removed for TouhouDB alone?