Now, if adding a `completed process instances only` filter to a report with an existing `running process instances only` (also other way round), we automatically remove the one that existed before. That behaviour is not expected by the user as it is not a direct consequence of user's actions.
- `completed process instances only` and `running process instances only` filters can exist simultaneously
- same filter of the ones mentioned above can not be added multiple times
- there's a warning message that explains why the user sees a report with empty data if incompatible filters are applied
- User Guide is adjusted accordingly
- the warning should also appear in the anaylsis page