add method and route to search across tracks, albums and artists.

+ break models into separate files
+ same for the utils and setup

app/api/favorites.py

@@ -3,7 +3,7 @@ from flask import Blueprint, request
 from app.db.sqlite.favorite import SQLiteFavoriteMethods as favdb
 from app.db.store import Store
 from app.models import FavType
-from app.utils import UseBisection
+from app.utils.bisection import UseBisection
 
 api = Blueprint("favorite", __name__, url_prefix="/")