(Fix) Handle nullability of SQLite rowid alias columns

[Lege19]

Does your PR solve an issue?

fixes #3967

Is this a breaking change?

This is a breaking change.
Previously an INTEGER PRIMARY KEY column was wrongly inferred to be nullable, so code using query! will break, as the result will now be an i64 instead of an Option<i64>.
query_as! should be fine though because Option<i64> implements From<i64>

This will apply anywhere someone has used an INTEGER PRIMARY KEY and not overridden the nullability of that column in their queries.