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##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
New Percona/MySQL 8 privileges with underscore is not working. 
the following error is coming 

`MSG: invalid privileges string: Invalid privileges specified: frozenset({'BACKUP_ADMIN'})`

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
mysql_user module
most likely the new privileges needs to be added to lib/ansible/modules/database/mysql/mysql_user.py

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

<!--- HINT: You can also paste gist.github.com links for larger files -->

pass
#
def use_old_user_mgmt(cursor):
    cursor.execute("SELECT VERSION()")
    result = cursor.fetchone()
    version_str = result[0]
    version = version_str.split('.')
    if 'mariadb' in version_str.lower():
        
        if int(version[0]) * 1000 + int(version[1]) < 10002:
            return True
        else:
            return False
    else:
        
        if int(version[0]) * 1000 + int(version[1]) < 5007:
            return True
        else:
            return False
def get_mode(cursor):
    cursor.execute('SELECT @@GLOBAL.sql_mode')
    result = cursor.fetchone()
    mode_str = result[0]
    if 'ANSI' in mode_str:
        mode = 'ANSI'
    else:
        mode = 'NOTANSI'
    return mode
def user_exists(cursor, user, host, host_all):