remove table cf_collection

[dustymc]

Source

#624

Summary

cf_collection is a relic of portals, and contains two types of information

1. Layout, which can be moved to collection
2. DB credentials for some public users, which may not be necessary at all - any that is needs moved to a dedicated table (or https://github.com/ArctosDB/internal/issues/357)

User Interface Changes

none

Data Structure Changes

significant simplification