##### SUMMARY
mysql_db module should be able to create/drop multiple databases

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
lib/ansible/modules/database/mysql/mysql_db.py

##### ADDITIONAL INFORMATION
Why and what it would solve:
Avoids repetitive tasks to create/delete more than one databases (similar to https://github.com/ansible/ansible/issues/56059)

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

- Create (Multiple databases)
```yaml
  tasks:
  - name: Create multiple databases (provided in comma separated form)
    mysql_db:
      name: bobdata, bobthebuilder
      state: present
  - name: Create multiple databases (provided in list form)
    mysql_db:
      name:
        - bobdata
        - bobthebuilder
      state: present
```

- Delete/Drop (Multiple databases)
```yaml
  - name: Delete/drop multiple databases (provided in comma separated form)
    mysql_db:
      name: bobdata, bobthebuilder
      state: absent
  - name: Delete/drop multiple databases (provided in list form)
    mysql_db:
      name:
        - bobdata
        - bobthebuilder
      state: absent
```

Credits for the idea to @Andersson007 from comment https://github.com/ansible/ansible/pull/56721#issuecomment-505128646
state:
    description:
      - The database state
    default: present
    choices: [ "present", "absent", "dump", "import" ]
  collation:
    description:
      - Collation mode (sorting). This only applies to new table/databases and does not update existing ones, this is a limitation of MySQL.
  encoding:
    description:
      - Encoding mode to use, examples include C(utf8) or C(latin1_swedish_ci)
  target:
    description:
      - Location, on the remote host, of the dump file to read from or write to. Uncompressed SQL
        files (C(.sql)) as well as bzip2 (C(.bz2)), gzip (C(.gz)) and xz (Added in 2.0) compressed files are supported.
  single_transaction:
    description:
      - Execute the dump in a single transaction
    type: bool
    default: 'no'
    version_added: "2.1"
  quick:
    description:
      - Option used for dumping large tables
    type: bool
    default: 'yes'
    version_added: "2.1"
  ignore_tables:
    description:
      - A list of table names that will be ignored in the dump of the form database_name.table_name