Feat flush view data

[viest]

The view data keeps appending causing memory to increase.

For example.

There is a timed task to send emails, I send 100 emails with different data, the view data length will be 100, the data volume is large but the memory is relatively small, it can easily lead to killed.

Add a method to clean up view data, users can clean up unnecessary data by themselves to protect memory.

for ($index = 0; $index < 100; $index++) {
    /* @var Factory $viewFactor */
    $viewFactor = Mail::getViewFactory();

    $view = $viewFactor->make('email.view', [
        // big data......
    ]);

    // get html
    $data = $view->render();

    /* @var CompilerEngine $viewEngine */
    $viewEngine = $view->getEngine();
    $viewEngine->flushViewData();

    // send mail via raw data
    // ......
}

[freekmurze]

Could you also document this function in the readme?

[viest]

I described what the function does through comments, does this meet your requirements?