Remove unknown options to the mysql2 initalizer

Nobody has claimed this yet.

## Suggestion

Is there any drawback to stripping connection options from the DataSource to the Mysql2 underlying connector?, I would ideally like to remove the emission of [this](https://github.com/sidorares/node-mysql2/blob/a1fd971eb76db3b3820fde5b80257d565888b258/lib/connection_config.js#L89) warning

```js
if (validOptions[key] !== 1) {
// REVIEW: Should this be emitted somehow?
// eslint-disable-next-line no-console
console.error(
`Ignoring invalid configuration option passed to Connection: ${key}. This is currently a warning, but in future versions of MySQL2, an error will be thrown if you pass an invalid configuration option to a Connection`
);
}
```

If there isn't anything against it, I would love to contribute with a pull request, the only drawback I can think of is that the validOptions aren't exported from the library.

(Sorry for not following the template, I didn't felt that the formats properly addressed what I wanted to communicate)

Start by tracing the Mysql2 initializer and checking how DataSource options reach the mysql2 connection_config.js validation linked in the issue. Confirm which options are supported and establish tests for the filtering behavior; done means unsupported options no longer trigger the warning while supported connection options continue to work.

Written by the indexing model from the issue text.