Rework Data Structure

[HenrZu]

Motivation / Current Behaviour

Currently, we have the following structure:
data

• mobility
• contacts
• pydata (optional, only created if epidata is called)
  However, the existing data in mobility/contacts is also regional dependent (right now only valid for Germany) and also created partially (Commuter_mobility) created with the pycode.

Therefore, a better structure would be
data

• Germany
  --- mobility
  --- contacts
  --- pydata
• Country2
  .....

Enhancement description

see description

Additional context

No response

Checklist

• Attached labels, especially loc:: or model:: labels.
• Linked to project