[Feature] Use pack API for generating /compare and /cycle comparisons

[3vorp]

Using the new pack tag system implemented with the pack API a few months ago, we can automate the creation of /compare displays. There's also a resolution field to sort by to ensure rows are correctly placed.

This might be a bit complicated since default packs need to be sorted correctly and the row placement needs to be right (faithful on top, cf jappa in the middle, cfpa on the bottom), but I imagine this can be accomplished using some sorting trickery.