Use schema.json instead of zoteroTypeSchemaData.js

[dstillman]

No one is going to remember to run build_typeSchemaData.html in a Zotero instance after updating schema and restarting and then copy the file into this submodule.

zoteroTypeSchemaData.js is currently used for Zotero.CachedTypes, Zotero.ItemTypes and Zotero.CreatorTypes. I believe the only thing in zoteroTypeSchemaData that's not in schema.json is icon filenames. Those would arguably make sense in schema.json, but that gets into some complicated questions about icon sizes, PNG vs. SVG, etc., so for now we should probably just port those functions to use schema.json and keep this file around for the icon info.