TMDM-7548: "Statistics rest services enhancement"

Adds support for "top" parameter in data service.
Adds support for "top" parameter in matching service.
Adds support for "timeframe" parameter in journal service.
Adds support for "timeframe" parameter in event service.
Improvement: TimeSlicer can now read upper and/or lower bound from query iso. querying database for min and max.
Journal service enhancement: Timeframe service for journal returns maximum 5 groups (step may vary depending of chosen timeframe).
Adds unit test for TimeSlicer.
(https://jira.talendforge.org/browse/TMDM-7548)