Add database utility scripts and dummy data for testing

[babrar]

RUN:

• gen_basketball_events.py > dummy_data_bb.sql to obtain a sql script containing events for basketball.
• gen_gridiron_events.py > dummy_data_gridiron.sql to obtain a sql script containing events for gridiron.
• Run \i dummy_data_bb.sql and \i dummy_data_bb.sql in Postgres shell to populate the basketball + gridiron tables.

Player names, Team names and League names can be easily edited in the Python script to customize dummy data.

Blast-radius: SAFE. Does not impact any other 1nil functionality.

[babrar]

@sid42 you can use these scripts to test your stats stuff locally. Can be merged to main without breaking changes.

@KnotScientific you can request for any custom data you'd want the database to have for the demo.

[sid42]

Merging to test basketball league RPC calls