DateAndTime to/from DATETIME is inconsistent

[rko281]

The unit test MySQLStatementReadTest>>testReadTimeTypes was previously running correctly in GMT timezone but now errors following the move to daylight saving time.

The cause looks to be the mapping of DateAndTime to/from DATETIME values. When converting to DATETIME the DateAndTime representation in the local timezone is used; this implicitly includes the local offset (the DATETIME representation does not include an offset). When converting back to a DateAndTime in MySQLBinaryReader>>dateTimeFrom: a zero offset is applied resulting in a different DateAndTime.

Note that MySQLStatementReadTest>>testReadTimeTypes only fails on the first attempt; subsequent runs succeed due to the test permanently changing the image's localTimeZone to TimeZone default (UTC).

Suggest changing MySQLBinaryReader>>dateTimeFrom: to apply the localTimeZone's offset instead of zero.