Fix/allow db via ssh

[joda9]

This pull request refactors database engine handling, improves configuration loading, and enhances table import logic for better maintainability and flexibility. The main changes include replacing the toep_engine with a more general egon_engine, refactoring config loading to handle time parsing robustly, and making table/schema mapping lazy-loaded and context-aware. Additionally, the table import logic is now more flexible for both remote and local databases.

Database engine and import logic refactor:

• Replaced the import and usage of toep_engine with egon_engine throughout edisgo.py to standardize database engine handling. [1] [2] [3] [4] [5]
• Refactored import_tables_from_oep in config.py to support both remote (OEP/toep) and local (egon_data) database engines, including dynamic ORM class creation for local databases.

Configuration and mapping improvements:

• Made DB table and schema mappings lazy-loaded via _ensure_db_mappings_loaded, improving performance and reliability for remote OEP access. [1] [2] [3]
• Changed default schema references from "model_draft" to "dataset" and improved error handling when importing modules and attributes for mappings. [1] [2]

Configuration file parsing enhancements:

• Centralized and robustified time parsing for demandlib configuration entries using _normalize_demandlib_times, replacing scattered manual parsing in both from_cfg and from_json. [1] [2] [3]

Miscellaneous improvements:

• Simplified the get function for config value retrieval by iterating over possible type accessors, reducing nested try/except blocks.
• Minor fix in test configuration to properly set pytest.engine_local when the --runlocal option is used.# Description