AT:

• a migration is added that maps the old configuration structure to the explicitly modeled 2.4 structure
• the new migration step can cope with reports from Optimize 2.2 and 2.3

Make sure that after the migration all fields of the new structure are present and initialized with their default values

Context:
With https://app.camunda.com/jira/browse/OPT-1807 the configuration structure for 2.4 got introduced.