Describe the bug

Imports using databases (besides the test OEP) do not work due to incorrect assumptions about table naming and missing documentation for SSH configurations. Additionally, it is not possible to open an SSH tunnel externally and use it with eDisGo.

To Reproduce

Steps to reproduce the behavior:

1. Attempt to import data from an eGon-data database (not the test OEP).
2. Observe that the import fails due to table naming mismatches.
3. Try configuring database connections using SSH tunneling outside of eDisGo.
   • eGon-data configuration files without ssh tunnel information are not currently supported.

Expected Behavior

• Database imports should work for any properly configured eGon-data database, not just the test OEP.
• The engine function should be well-documented for handling eGon-data configurations and SSH settings.
• Users should be able to open an SSH tunnel externally and use it with eDisGo.