Function insert_solution_set_submission 

pub fn insert_solution_set_submission(
    tx: &Transaction<'_>,
    solution_set: &SolutionSet,
    timestamp: Duration,
) -> Result<ContentAddress>

Insert a submitted solution set and the time it was received into the table.

This first inserts the solution set and its CA into the solution set table if it doesn’t already exist, then inserts associated timestamp into the submission table.