Flight SQL JDBC: Fix timezone/timestamp handling

### Describe the enhancement requested

I believe the JDBC driver is handling timezones/timestamps/java.sql.Timestamp entirely incorrectly.

- Timestamps are round-tripped through LocalDateTime always. I believe this is wrong for timestamps with timezones: we should not round trip through a wall clock time since the same wall clock time may correspond to multiple different instants (during a DST transition)
- From experimenting with the PostgreSQL JDBC driver, it appears that when requesting a java.sql.Timestamp, the expected behavior is:

- Naive timestamp: return a Timestamp that appears to have the right wall clock time in the given Calendar, or the system time zone if no calendar is supplied. (In other words, use Timestamp as a janky LocalDateTime.)
- Zoned timestamp: return a Timestamp whose value is the timestamp in UTC. (In other words, use Timestamp as an Instant.)

It appears our driver does not do this properly.

首先跟踪 Flight SQL JDBC driver 对 java.sql.Timestamp、LocalDateTime、时区和 Calendar 的处理方式，并将其行为与 issue 中描述的 PostgreSQL JDBC 预期进行比较。完成的标准是：无时区时间戳保留请求的墙上时钟值，带时区的时间戳保留 UTC 时刻，包括跨越 DST 转换时的行为。

由索引模型根据 Issue 内容生成。