Face labeling workflow: Retain "unknown" status for faces after face training

[ChrisFab16]

Face training allocates all unknown faces to best guess candidates.

Introducing a minimum confidence level would ensure that uncategorized faces could be selected

[jakekapellen]

Is this fixed by the migration to HDBSCAN? HDBSCAN relies on higher-density clustering, so it filters out noise points quite well.

[derneuere]

I think I will close these issue, as these should be fixed :)