Add smart collection term for "Black exclamation circle" icon

Note that the black-circle-exclamation icons, which indicates a file is damaged, unsupported, or unreadable, are ephemeral. They only appear after LR tries to read the files (e.g. in Develop or building previews), and they go away after you restart LR.

While waiting for Adobe to provide a better way for searching for them, see this post for a slow but reliable method for finding all such files:

https://www.lightroomqueen.com/community/threads/validating-all-your-cataloged-photos-and-videos-for-corruption.51433/

> “Black exclamation circle” icon is added for errors in corrupted mage files

That is not what the “!” in a circle means.   Wwhat it means is that this is a parent folder where at least one sub-folder (at any level below this parent) is missing.  The folder that is actually missing has a “?” on the folder icon.