[Feature Request]: "pack=" search prefix

Is there an existing issue for the feature?

[X] I have searched the existing feature requests

Describe the Feature

Along with the other search prefixes such as "artist=", there should be one that filters one pack or a group of packs using a "pack=" prefix, so that they can only see packs from 1 series, groups of packs that have important keywords (e.g "pack=chordjack" would should all packs with chordjack in the name), or only filter out a singular pack.

How Does The Feature Add To The Game?

In Etterna, it is currently possible to search using a myriad of different specifications to narrow down the number of files available for them, which would be particular helpful for players who are picking songs with the randomize feature. Therefore, it only makes sense that the ability to filter with pack names to allow only one pack, or a group of packs with similar names, should be available to the player.

Additional Context

Unsure of what exactly must be changed to add this feature, but most likely could be copied and changed from one of the other existing filters.

etternagame / etterna