WIP: Add minimap worker to test stresm switching
Minimal worker and test for it demonstrates what happen by stream switching.
Following actions are expected:
- Create several streams in one data_source use for testing
- Each stream consist of one message
- Create data_source for metadata with one stream and one message
- Run minimal worker
- Worker should go across all input streams and for each input stream create output stream
- After first message it gets stream finish flag from input stream and should send stream finish flag to output stream