60 Cleanup

[baseTwo]

Create separate prs
Evaluate how much time is left for remaining important issue

• Clean up the LibrarySet, extract the topology sort into a separate utility. LibrarySet should not contain any state other than keeping a set of libraries
• Use Maybe for return type on all TryXXX methods
• Remove scoped services in CQL and ELM apis, will need improvement on the tuple cache
• There are more than a 100 TODO comments in the repo
• Consider moving internal types to a subnamespaces Internal
• Cleanup the debug assertions in the cql to elm package (speak to Evan)