These used to work because there was a huge blocking load operation,
which is now more asynchronous.
Note that the change made in `SongSelect` is not required, but defensive
(feels it should have been doing this the whole time).
One of my pending work items for post-realm merge.
The lowest-level import task is no longer asynchronous, as we don't want
it to span multiple threads to allow easier interaction with realm.
Removing the `Task` spec simplifies a heap of usages.
Individual usages should decide whether they want to run the import
asynchronously, by either using an alternative override or spooling up a
thread themselves.