Audit and fix 24:00 handling for Time/TimeTZ

[otan]

Postgres has a unique max time of 24:00:00 for both TimeTZ and Time.

They can be stored/parsed as 24:00:00:

otan=# select '24:00'::time;
   time
----------
 24:00:00
(1 row)

otan=# select '24:00:00'::timetz;
   timetz
-------------
 24:00:00-08
(1 row)

But not "added" to '24:00:00':

otan=# select '23:59'::time + '1min'::interval;
 ?column?
----------
 00:00:00
(1 row)

Our timeofday library for parsing time/timetz (timeofday.New) or inferring time (timeofday.FromInt) always assumes that we should round -- but there are cases (such as cli/dump.go) where we should actually NOT round when doing this.

We should audit and fix all the cases where rounding is not desired.

This was caught "by accident" in #44459.

[otan]

turns out to not be a problem.

[awoods187]

Could you expand upon this further @otan ?

[otan]

The real problem is #44548