Allow detection of missing map data from other loaded collections

[Kuuuube]

This main use case for this would be the ability to upload a single collection with unknown maps to osu!Stats then have all other loaded collections pull data from that identified collection.

Doing this automatically would probably create issues so adding a button for it in the gui or even adding it exclusively for the CLI would be nice (potentially allowing a .osdb as a substitute for the osu!.db).