[jdbc-v2,client-v2] Fix logging issues

[chernser]

Description

After a review next bugs in logging should be fixed:

• StatementImpl.java:226 logs the wrong exception. The catch variable is ex, but the log call passes e
• HttpAPIClientHelper.java:1031-1033 can throw ClassCastException inside the retry decision. The condition accepts the case where the cause is a ServerException, but the cast only handles the case where ex itself is one.
• HttpAPIClientHelper.java:1127 LOG.info("failed to construct http client version string") — wrong level for a important user-agent problem, and it discards the exception it just caught, so it can't be acted on either way. This one is both useless and mis-levelled.

[chernser]

@polyglotAI-bot implement this task, please