Fix: convert Python datetime objects to java.sql.Timestamp for parameter binding (legacy #70)

[HenryNebula]

Description

When calling cursor.execute() with Python datetime.datetime or datetime.date objects as parameters, JPype raises No matching overloads found for setObject because it cannot automatically convert Python datetime types to java.sql.Timestamp or java.sql.Date.

This affects stored procedure calls and parameterized queries that pass datetime values.

Steps to Reproduce

import jaydebeapi
conn = jaydebeapi.connect(driver_class, jdbc_url, [user, pass], jars)
cursor = conn.cursor()
cursor.execute("{call sp_UpsertTS(?,?,?,?,?,?)}", (id, datetime_obj, end_time, userid, pairid, username))
# RuntimeError: No matching overloads found for setObject

Expected Behavior

Python datetime.datetime should be automatically converted to java.sql.Timestamp, and datetime.date to java.sql.Date before being passed to PreparedStatement.setObject().

Legacy Reference

baztian/jaydebeapi#70

[HenryNebula]

Triage fix: #89