Rebalance SUS book itemgroups

[chaosvolt]

Summary

SUMMARY: Balance" Tone down book spam of Specific Use Storage book itemgroup collections, bundle more book spawns into distributions in said collections"

Purpose of change

Another entry in the "makin' SUS less sus" series, this time targeting specialized bookcase spawns. Fixes #2626

Describe the solution

Updated and overall reduced spawns of books in data/json/itemgroups/SUS/library.json. In general magazines lean towards 1-3 spawns at 75% chance, standard textbooks/manuals lean towards 1 or 1-2 spawns at 50% chance, and top-tier or specialist books as low as 1 spawn at 25% chance.

Itemgroups with a huge number of potential spawns have also had more uses of distributions inside them, aimed at condensing spawns of similar-themed books into a single attempt to spawn one of each. SUS_field_manual_bookcase also had a couple related manuals added to the collection to add more variety, books specifically noted to be books for military use but aren't explicitly FMs or TMs. Doesn't matter in practice since the mil-surp store is the only place that even uses that itemgroup.

Describe alternatives you've considered

Converting all of them into pure distributions instead of collections, requiring every spawn of them in mapgen to be edited to call them multiple times.

Testing

Checked affected file for syntax and lint errors.

The infamous tailoring bookcase, before:

And after:

Additional context