API: Overall refactor of API parameters
The filter parameter is a way to manipulate directly the SQL query. This was useful at the beginning, where the API was quite slow. Since a complete refactor of the API, it is possible to filter against the whole entity object, not only the database columns. Also, the sort mechanism can be redone to cover more use cases.
Since this will not break the endpoints, it might change the way, how all parameters will be used.