### 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)

with MySqlContext(client):
            records = ("foo", "bar", "baz")
            import tempfile
            with tempfile.NamedTemporaryFile() as f:
                f.write("\n".join(records).encode("utf8"))
                f.flush()
                hook = MySqlHook("airflow_db", local_infile=True)
                with closing(hook.get_conn()) as conn:
                    with closing(conn.cursor()) as cursor:
                        cursor.execute(
                            """
                            CREATE TABLE IF NOT EXISTS test_airflow (
                                dummy VARCHAR(50)
                            )
                        """
                        )
                        cursor.execute("TRUNCATE TABLE test_airflow")
                        hook.bulk_load("test_airflow", f.name)
                        cursor.execute("SELECT dummy FROM test_airflow")
                        results = tuple(result[0] for result in cursor.fetchall())
                        assert sorted(results) == sorted(records)
    @pytest.mark.parametrize("client", ["mysqlclient", "mysql-connector-python"])
    def test_mysql_hook_test_bulk_dump(self, client):