Added timeline feature
UserHistory table is a collection of events for all user.
To display timeline, first query the table to get events for
only the specific user, sort it by timestamp
and then populate the timeline.

TBD:
Right now used dummy data to populate UserHistory table
To be Implemented -
Use triggers to populate UserHistory table, whenever
OwnsGames gets populated.

Signed-off-by: Saikat <rychwdh2@illinois.edu>