Fix interval overflow

[reibitto]

I noticed issues with interval after upgrading to 42.2.9 from 42.2.8. It appears #1612 is the cause due to overloading issues. Some of the units were changed from int to byte. But I don't believe this is sound because intervals in postgres aren't guaranteed to be justified. For example, it's valid to have hour values greater than 24 hours:

select interval '900 hours';
-- 0 years 0 mons 0 days 900 hours 0 mins 0.00 secs

select justify_interval(interval '900 hours');
-- 0 years 1 mons 7 days 12 hours 0 mins 0.00 secs

I have unjustified intervals in my DB which is how I discovered this.

[davecramer]

Thanks, I was never truly happy with this change