Implement generating reports of patients and encounters

[mateuszkrasucki]

1. To allow clinic management to analyse the data about functioning of the clinic report generating needs to be implemented.
2. Each report should contain anonymised list of all patients and list of encounters that happened at the clinic in specified time period.
3. The job generating reports should run on cloud node and expose files in a way that they will accessible from cloud dashboard.
4. In the first step the report will be generated as CSV files, in the future possibly straight .xlsx.