This is one step closer to sanity in terms of physical files. As per the
comment I have left in place, we really should be checking file sizes or
hashes, but to keep things simple and fast I've opted to just cover the
"missing file" scenario for now.
Ran into this when testing against a foreign `client.realm` by:
- Noticing a beatmap doesn't load
- Deleting said beatmap
- Downloading via beatmap overlay
- Beatmap is restored but still doesn't work
Note that I've kept the logic where this will undelete an existing
import rather than create one from fresh, as I think that is beneficial
to the user (ie. it will still keep any linked scores on restore).
I've updated all cases where we should have been using
`GetDisplayString()` anyway, but left the `ToString()` implementations
in place for safety. They should probably be removed in the future.
This only occurs on upcoming changes I have (occurred when switching
existing skin import tests across to realm). Unsure why it was set to
`true`, seems like a weird oversight.
