Allow moving a table to different schema with ALTER TABLE ... RENAME

Support moving a table to another schema with ALTER TABLE RENAME.

Currently:
MariaDB [(none)]> create database a1;
Query OK, 1 row affected (0.001 sec)

MariaDB [(none)]> create database a2;
Query OK, 1 row affected (0.000 sec)

MariaDB [(none)]> create table a1.t1 (id int)engine=columnstore;
Query OK, 0 rows affected (0.355 sec)

MariaDB [(none)]> use a1;
Database changed
MariaDB [a1]> alter table t1 rename a2.t1;
ERROR 1178 (42000): The storage engine for the table doesn't support Both tables must be in the same database to use RENAME TABLE