Pasre data for connection string of orm from .env

[JDRkow]

Create a custom file reader for parsing data for connection for odb.

User story:
As a developer, I want to set up credential stuffing in database connection strings, so that I can hide sensitive data and keep all the data in one place.

DoD:

• Configure environment variable extraction in src/main.cpp for ODB.
• Configure environment variable extraction in src/data/alembic.ini for alembic.
• Create a .env.example file listing the project's environment variables.