SQL function toTimezone() converts a Date or DateTime into another
timezone. The problem is that the timezone is part of the Date /
DateTime type but not part of the internal representation (value). This
led to the fact that toTimeZone() wqith non-const timezones produced
wrong and misleading results until #48471 (shipped with v23.4) enforced
a const timezone.
Unfortunately, this PR also broke existing table definitions with
non-const timezones, e.g. in ALIAS expressions. So while #48471
addressed the issue appropriately, it is really backwards-incompatible.
This PR adds a setting to toggle the behavior and makes it also part of
the compatibility profile.
