Flask appbuilder test - added access control

[pardf]

Added user access control functionality

• using flask and its extensions particularly flask-login and flask-sqlalchemy
• flask code update and cleanup
• modifications in the dash app to work with flask access control
• updated web tests (x2)
• improved config.py for app setup and secrets management
• updated requirements by removing unused dependencies

[pardf]

Hi @kariso2000, currently, SECRET_KEY in config.py needs to be disabled to pass all checks.

However, in local run, disable the above means the app cannot be started.

[pardf]

Please remove ai4good/webapp/db.sqlite. This was created by me when I was testing some other code.

Hi @kariso2000 db.sqlite removed as requested