Introduce Pipenv

Replace requirements.txt with pipenv for consistent development environments. Pipenv maintains a superior Lockfile similar to NPM. Added additional development dependencies and mypy configuration.

This contains a package update too:

• alembic from 1.12.1 to 1.13.2
• flask from 3.0.0 to 3.0.3
• SQLAlchemy from 2.0.23 to 2.0.31

README.md

@@ -51,9 +51,9 @@ sudo docker exec -it portal-app-1 flask shell
 
 ```bash
 # mkdir yourself into the portal directory
-python3 -m venv venv
-source venv/bin/activate
-pip install -r requirements.txt
+# Have pipenv (pip install pipenv) installed
+pipenv install
+pipenv shell
 export FLASK_APP=portal
 alembic upgrade head # to create (and update!) the database
 flask run
@@ -63,9 +63,8 @@ Also, you have to set up the LDAP server in Flask. At the moment we are required
 
 ```sh
 sudo ssh -D <your_forwarded_port> -p 80 <username>@lennon.cl.uni-heidelberg.de -L 636:ldap2:636
-python3 -m venv venv
-source venv/bin/activate
-pip install -r requirements.txt
+pipenv install
+pipenv shell
 export FLASK_APP=portal
 alembic upgrade head # to create (and update!) the database
 flask run