Populate the flow activity table

Need to populate the flow_activity table

-Stores per day flow run pointers and info
-Written to by RM’s collector for application lifecycle
primary key: cluster ! day timestamp ! user ! flow id
-For the day timestamp we can take the millis since epoch for the end of the day (24:00h).
columns include runids, start time, end time, snapshot time
-This table will also be used to efficiently retrieve the flows that had an activity in a certain day. That is needed for daily aggregations, but also for several UIs, including a flow-based UI.