consolidate all of the angular API service code into the main services.js file.  we were mostly going this route already, but this just makes it simple and puts all the api code in a single place.

add a function in our schema metadata lib for `foreignKeyCountsByOriginTable` which counts the occurrences of FK relationships by the origin table they come from.  this allows us to know if a given origin table is represented multiple times in a list of FKs.