### Description

There is currently no way to pass an `init_command` connection argument for a mysql connection when using either the `mysqlclient` or `mysql-connector-python` libraries with the MySql provider's `MySqlHook`.

Documentation for connection arguments for `mysqlclient` library, listing `init_command`:
https://mysqlclient.readthedocs.io/user_guide.html?highlight=init_command#functions-and-attributes

Documentation for connection arguments for `mysql-connector-python` library, listing `init_command`:
https://dev.mysql.com/doc/connector-python/en/connector-python-connectargs.html

There can be many uses for `init_command`, but also what comes to mind is why do we explicitly provide support to certain connection arguments and not others?

### Use case/motivation

For my own use right now I am currently am subclassing the hook and then altering the connection arguments to pass in `init_command` to set the `time_zone` session variable to UTC at connection time, like so:

```python
conn_config['init_command'] = r"""SET time_zone = '+00:00';"""
```

Note: This is just an example, there can be many other uses for `init_command` besides the example above. Also, I am aware there is a `time_zone` argument for connections via the `mysql-connector-python` library, however that argument is not supported by connections made with `mysqlclient` library. Both libraries do support the `init_command` argument.

### Related issues

_No response_

### Are you willing to submit a PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

"""
        Convert argument to a literal.
        The package MySQLdb converts an argument to a literal
        when passing those separately to execute. Hence, this method does nothing.
        :param cell: The cell to insert into the table
        :param conn: The database connection
        :return: The same cell
        """
        return cell
    def get_iam_token(self, conn: Connection) -> tuple[str, int]:
        """
        Retrieve a temporary password to connect to MySQL.
        Uses AWSHook to retrieve a temporary password to connect to MySQL
        Port is required. If none is provided, default 3306 is used
        """
        from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook
        aws_conn_id = conn.extra_dejson.get("aws_conn_id", "aws_default")
        aws_hook = AwsBaseHook(aws_conn_id, client_type="rds")
        if conn.port is None:
            port = 3306
        else:
            port = conn.port
        client = aws_hook.get_conn()
        token = client.generate_db_auth_token(conn.host, port, conn.login)
        return token, port
    def bulk_load_custom(