[DBAL-552] Fix parsing backtick quoted statement fragments in SQLParserUtils

MySQL uses backtick for identifier quotation. The `SQLParserUtils` treats statements with quoted identifiers that contain a colon as named parameter which is wrong.

**Example**
```sql
SELECT `d.ns:col_name` FROM my_table d WHERE `d.date` >= :param1
```

**Throws exception**
```
An exception occurred while executing 'SELECT `d.ns:col_name` FROM my_table d WHERE `d.date` >= :param1' with params ["2013-06-24 14:22:18"]: Value for :col_name not found in params array. Params array key should be "col_name"
```

This PR adds the backtick character to the recognized quote characters when retrieving unquoted statement fragments.