update database model

Update database model with the following:

- [X] Remove apps table - all projects have them all by default
- [X] Add image table from previous ImageSpace app
- [X] Added user and team tables for future user registration
- [X] Added DataModels in crawls (A crawl if crawler=ACHE needs a classifier model, the app can let you select an existing one or generate one, providing positive and negative examples)
- [X] Hotfix - Added FK to some tables