[Userscript] Item List Filter (for Self-Study Quiz)

@rfindley this is a bug report.

I have tested this script with Item Inspector.

The new filter shows in the Item Inspector settings and I can configure it. Item Inspector uses this filter but it seems that there is a bug. Not all items in the list show up in the table. I tried the same configuration with Self-Study Quiz and I have the same bug there too. So it seems to be a problem with the filter itself.

The problematic configuration:

Only the radicals ground and gambler and the kanji 一 are shown in the table or used in a quiz. The other two kanji and the vocabulary items don’t show up.

For testing purposes I find that Item Inspector is more convenient than Self-Study Quiz because it displays all items at once on the dashboard. You can see at a glance if something is missing instead of having to run through a quiz.