[fix] Potentially rewrite update, add and getJson in utilities.py

[cbloodsworth]

Right now the fields on any given resume, section or entry are kind of set-in-stone: if you want to add a new field, for example an "image_preview" on the resume object, you need to manually add that to DBHelper's addNewResume, getJsonResume, and updateResume function.

These functions generally do some kind of conversion of database object to JSON or the other way around, and when copying fields from one to the other, they each are hard coded.

A solution might be to maybe pull some of the functionality into a separate method on its own, or be more strict about the way we parse json? Not sure the best solution here. Maybe we could have some list somewhere that stores all field names that we should copy over and iterate over that. I'll look at this in the future