Use database onboarding process configuration instead of properties

[banterCZ]

Task specification

Right now, the onboarding process configuration is hardcoded in properties. A new database structure has been introduced in #1344, but it is not yet used by the backend logic.

We should consider documents (types, count ...) and OTPs. This list might not be complete. Investigate further.

[zcgandcomp]

Proposed JSON structure:

documents": {
    "requiredDocumentsCount": 2,
    "groups": [
      {
        "requiredDocumentsCount": 1,
        {
          "type": "ID_CARD",
          "sideCount": 2
        },
        {
          "type": "PASSPORT",
          "sideCount": 1
        }
      },
      {
        "requiredDocumentsCount": 0,
        {
          "type": "DRIVING_LICENCE",
          "sideCount": 1
        },
        {
          "type": "STAY_PERMIT",
          "sideCount": 1
        }
      },
    ]
  }