Make SQLite ADBC C99 compatabile

[WillAyd]

What feature or improvement would you like to see?

Right now the sqlite driver makes use of the gmtime_r function, which is not part of the C standard until C23, though it exists as a POSIX extension for C99

I'm assuming we want to work with the C99 standard (or maybe even something new, but not quite as new as C23) so need to replace that function usage

[WillAyd]

Looks like utils also makes use of strdup, which has the same limitations

[lidavidm]

I guess we should port this stuff to C++ instead, and possibly vendor something like https://github.com/HowardHinnant/date ?

[WillAyd]

Certainly a long term option, though in the meantime I think could just remove the gmtime_r usage. ~It looks like it is macro'd in when available, with the non-POSIX branch using a mutex around gmtime; the latter could suffice if we wanted strict C99 (or later) compliance~

Edit: the vendored sqlite source has a good way of handling