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

Pipfile

+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+alembic = "*"
+argon2-cffi = "*"
+flask-sqlalchemy = "*"
+flask = "*"
+ldap3 = "*"
+requests = "*"
+sqlalchemy = "*"
+
+[dev-packages]
+black = "*"
+mypy = "*"
+types-requests = "*"
+types-ldap3 = "*"
+
+[requires]
+python_version = "3.12"
+python_full_version = "3.12.4"