[Feature Request]: Use sql to delete all unlinked entries simultaneously

[Toby222]

Checklist

• I am using an up-to-date version.
• I have read the documentation.
• I have searched existing issues.

Description

As per this TODO:
Currently when deleting unlinked entries, they are deleted one-by-one, only so they can update the progress bar.
I believe it would be better to let the progress bar be indeterminate and speed up the deletion by deleting all items in parallel.
In brief testing the speedup was significant enough that the progress bar was no longer visible long enough for the lack of visible progress to matter :^)

Solution

Instead of calling remove_entries with one id at a time, pass all relevant IDs simultaneously.

Alternatives

No response