### 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)

if TYPE_CHECKING:
    try:
        from mysql.connector.abstracts import MySQLConnectionAbstract
    except ModuleNotFoundError:
        logger.warning("The package 'mysql-connector-python' is not installed. Import skipped")
    from MySQLdb.connections import Connection as MySQLdbConnection
MySQLConnectionTypes = Union["MySQLdbConnection", "MySQLConnectionAbstract"]
class MySqlHook(DbApiHook):
    """
    Interact with MySQL.
    You can specify charset in the extra field of your connection
    as ``{"charset": "utf8"}``. Also you can choose cursor as
    ``{"cursor": "SSCursor"}``. Refer to the MySQLdb.cursors for more details.
    Note: For AWS IAM authentication, use iam in the extra connection parameters
    and set it to true. Leave the password field empty. This will use the
    "aws_default" connection to get the temporary token unless you override
    in extras.
    extras example: ``{"iam":true, "aws_conn_id":"my_aws_conn"}``
    You can also add "local_infile" parameter to determine whether local_infile feature of MySQL client is
    going to be enabled (it is disabled by default).
    :param schema: The MySQL database schema to connect to.
    :param connection: The :ref:`MySQL connection id <howto/connection:mysql>` used for MySQL credentials.
    :param local_infile: Boolean flag determining if local_infile should be used
    """
    conn_name_attr = "mysql_conn_id"
    default_conn_name = "mysql_default"
    conn_type = "mysql"
    hook_name = "MySQL"
    supports_autocommit = True
    def __init__(self, *args, **kwargs) -> None: