##### SUMMARY

`mysql_info` module doesn't show empty DBs. It uses following query in the code:

```
MariaDB [(none)]> SELECT table_schema AS 'name', SUM(data_length + index_length) AS "size" FROM information_schema.TABLES GROUP BY table_schema;
+--------------------+-----------+
| name               | size      |
+--------------------+-----------+
| d106953_tm         | 470728704 |
| information_schema |    212992 |
| mysql              |   6038300 |
| performance_schema |         0 |
+--------------------+-----------+
4 rows in set (0,005 sec)
```
But `show databases` show something else;
```
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| d106953_tm         |
| information_schema |
| innodb             |
| mysql              |
| performance_schema |
| testovic           |
| tm_web             |
| ttttt              |
+--------------------+
8 rows in set (0,001 sec)
```

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
`mysql_info` modules

##### ANSIBLE VERSION
```
ansible 2.9.1
  config file = /home/jiri/.ansible.cfg
  configured module search path = ['/home/jiri/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /home/jiri/stow/ansible/venv/lib/python3.6/site-packages/ansible
  executable location = /home/jiri/stow/ansible/venv/bin/ansible
  python version = 3.6.9 (default, Nov  7 2019, 10:44:02) [GCC 8.3.0]

```

##### OS / ENVIRONMENT
Amazon Linux 2
rh-mariadb103-3.3-5.el7.x86_64

##### STEPS TO REPRODUCE

* create empty via eg. via `mysql_db module`
* query via `mysql_info` what databases where found

##### EXPECTED RESULTS
should list even empty DBs

##### ACTUAL RESULTS

it seems only populated DBs are listed
description: Master status information.
  returned: if master
  type: dict
  sample:
  - { "Binlog_Do_DB": "", "Binlog_Ignore_DB": "mysql", "File": "mysql-bin.000001", "Position": 769 }
slave_status:
  description: Slave status information.
  returned: if standby
  type: dict
  sample:
  - { "192.168.1.101": { "3306": { "replication_user": { "Connect_Retry": 60, "Exec_Master_Log_Pos": 769,  "Last_Errno": 0 } } } }
slave_hosts:
  description: Slave status information.
  returned: if master
  type: dict
  sample:
  - { "2": { "Host": "", "Master_id": 1, "Port": 3306 } }
'''
from decimal import Decimal
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.mysql import (
    mysql_connect,
    mysql_common_argument_spec,
    mysql_driver,
    mysql_driver_fail_msg,
)
from ansible.module_utils.six import iteritems
from ansible.module_utils._text import to_native
#
class MySQL_Info(object):