##### 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
module.fail_json(msg="Please provide at least one database name")
    encoding = module.params["encoding"]
    collation = module.params["collation"]
    state = module.params["state"]
    target = module.params["target"]
    socket = module.params["login_unix_socket"]
    login_port = module.params["login_port"]
    if login_port < 0 or login_port > 65535:
        module.fail_json(msg="login_port must be a valid unix port number (0-65535)")
    ssl_cert = module.params["client_cert"]
    ssl_key = module.params["client_key"]
    ssl_ca = module.params["ca_cert"]
    connect_timeout = module.params['connect_timeout']
    config_file = module.params['config_file']
    login_password = module.params["login_password"]
    login_user = module.params["login_user"]
    login_host = module.params["login_host"]
    ignore_tables = module.params["ignore_tables"]
    for a_table in ignore_tables:
        if a_table == "":
            module.fail_json(msg="Name of ignored table cannot be empty")
    single_transaction = module.params["single_transaction"]
    quick = module.params["quick"]
    if len(db) > 1 and state != 'dump':
        module.fail_json(msg="Multiple databases is only supported with state=dump")
    db_name = ' '.join(db)
    if state in ['dump', 'import']:
        if target is None:
            module.fail_json(msg="with state=%s target is required" % state)
        if db == ['all']: