Only allow [a-zA-Z0-9_-]{1,63} as table names

We saw tables having '%' in their names getting created. This got
replication stuck. Hence, we're limiting allowed table names to
alphanumeric characters plus underscore and dash.

The reliable limit of table name length for MySQL is 63. Hence, we
limit to 63 characters.

RT: 9016
Change-Id: I14460b25dbf44867c0213080b401b3b7185fb2aa