Add indicator for delisted mods

[Marioalexsan]

Closes #1988.

Implements a delist indicator for installed mods. A mod is considered as delisted if its install type is "managed", and a corresponding Thunderstore entry was not found for the installed mod. This likely means that the mod has either been rejected, or was delisted completely from Thunderstore.

This is an example of how it would look like with mods from the Atlyss community:

• BepInExPack, AppearancePlus by Nuilescent, CodeTalker by Robyn and EasySettings by Nessie are managed installs
• AppearancePlus is present in Thunderstore, but deprecated, so it shows up using its usual Deprecated tag
• CodeTalker has been delisted from Thunderstore, so it shows up using the new Delisted tag

Delisted packages that are locally installed remain untagged, meaning an equivalent local install of CodeTalker would remain unaffected.

[ebkr]

Have you tested this with a locally installed package? There isn't a case (that I can immediately see) where "managed" is never not the install mode.