The structure of the data field of the combined report looks currently like the following:
This has two problems:
- In the configuration we have a "reportColor":  field that contains the color for each report that belongs the combined report. If one report is deleted, we need to make sure that this is also automatically done for the color to keep the configuration consistent.
- The combined report configuration contains a lot of configuration properties that it just doesn't need.
Hence, we should rather have a structure like this following:
- the combined report data restructure has been changed, such that the report color is not stored in the configuration field any longer and the configuration field only contains entries that belong to the combined report
- the configuration field of the single report does not contain configuration properties of the single report any longer
- the rest API documentation has been adjusted accordingly