Add Special Filter Options for Empty/Null Value

[shin-go]

Use case is when a Library has content that is a mash up of items that have proper metadata (from whatever source) for things like Author, Publisher, etc. intermingled with content that doesn't have that metadata, it becomes - as far as I'm aware - quite difficult to track down what is missing metadata until you stumble upon it by chance.

In 1.19.1 filters on just about everything allow for Include/Exclude toggling, but when attempting to identify content that is not tagged, there is no value for that particular facet of metadata being empty/null. In very large Libraries, you could technically accomplish this by selecting every possible value you want to filter on and make it an Exclusion. For obvious reasons, that's not particularly viable. A special value that is filterable would be very appreciated and useful!

[gotson]

It's possible for some filters like authors, with a negative 'Any' filter:

Would need to be added to other fields indeed.

[gotson]

I've added this for tags, genres, publishers, language, release dates, and sharing labels

[gotson]

🎉 This issue has been resolved in 1.21.0 (Release Notes)