…nary digest test (#58291)

Related PR: #56497

Problem Summary:

The test `test_binary_for_digest` was failing when running Regression
External tests because it depended on a pre-existing `doris_test`
database in the external MySQL instance. This database is only created
during query_p0 test suite execution, which will cause error:
```text
Exception in query_p0/sql_functions/encryption_digest/test_binary_for_digest.groovy(line 51):

        connect("root", "123456", "jdbc:mysql://${externalEnvIp}:${mysql_port}/doris_test?useSSL=false") {
            try_sql """DROP TABLE IF EXISTS ${test_table}"""

            sql """CREATE TABLE ${test_table} (
                id int,
                vb varbinary(100),
                vc VARCHAR(100)
            )"""

            sql """INSERT INTO ${test_table} VALUES 
^^^^^^^^^^^^^^^^^^^^^^^^^^ERROR LINE^^^^^^^^^^^^^^^^^^^^^^^^^^
                (1, 'hello world', 'hello world'),
                (2, 'test data', 'test data'),
                (3, 'hash test', 'hash test'),
                (4, '', ''),
                (5, 'special chars: !@#%', 'special chars: !@#%')"""
        }

        sql """switch ${catalog_name}"""
        sql """use ${ex_db_name}"""


Exception:
java.sql.SQLSyntaxErrorException: Table 'doris_test.binary_test' doesn't exist
```

Now creates `binary_for_digest_test` database at test startup instead of
relying on `doris_test`.