Add all dataset paths to config

[Hussein-Mahfouz]

It is difficult to document the exact dataset names and directory structure. We have strange names such as ODWP01EW_OA. We should:

• Clean up data/external and give standard names
  • add all datasets to subfolders
• Add paths to specific datasets in the config and remove hardcoded data names from the scripts. I think this would help us avoid users running into file not found type errors
  • example of hardcoding:

    acbm/scripts/3.2.2_assign_primary_zone_work.py

    Line 79 in 87fa6be

    acbm.root_path / "data/external/ODWP15EW_MSOA_v1.zip"