databases/mysql-connector-odbc: New port

MySQL Connector ODBC is an ODBC driver for interfacing to MySQL
databases.

Please note that this port is the successor of mysql-connector-odbc-80.
The older port is no longer required as the older port was mysql version
agnostic which is no longer the case with the connector ODBC. The older
port has been removed in this same commit and relevant MOVED entry has
been added. The new port also supports differet flavors of ODBC engines.
The default flavor is unisodbc which is backed by unixODBC engine and the
other iodbc backed by iodbc engine.

WWW: https://www.mysql.com/