Modifying dbccdb schema for large identifiers

[CR #400680] The dbccdb database does not support workspace names longer than 30 characters.

Workaround:

  1. In the dbcc_exclusions table in dbccdb, modify the table_name column from varchar(30) to varchar(255).

  2. In sp_dbcc_run_evaluatedb, modify the @wsname local variable from varchar(30) to varchar(255).