Add ability to access downloaded files and read them into InputStream via API call to Selenium Host

[dmitry-minchuk]

This is already done in Selenoid: Link
Why not to do the same for dockerized Selenium/Seleniarm?

We will have to just build a correct URL like that:
GET http://selenium-host:4444/download/f2bcd32b-d932-4cdc-a639-687ab8e4f840/myfile.txt

There are numerous advantages of such approach:

1. No mess with file management - all the downloaded files will be wiped with the browser container
2. No file system access permissions issues
3. No issues with accessing file system when server instances are provisioned automatically and configuration in that case may be tricky

Java code in this case looks simple:

private static InputStream download(String fileName) {
    String url = String.format(fullMethodUrl, BrowserController.getSessionId().get(), fileName);
    InputStream file = null;
    HttpRequest request = HttpRequest
            .newBuilder()
            .uri(URI.create(url))
            .GET()
            .build();
    HttpResponse<InputStream> response;
    try {
        response = HttpClient
                .newHttpClient()
                .send(request, HttpResponse.BodyHandlers.ofInputStream());
    } catch (IOException | InterruptedException e) {
        e.printStackTrace();
        return null;
    }
    file = response.body();
    return file;
}

[VietND96]

Access download file via client bindings, I think you can refer to this https://www.selenium.dev/documentation/webdriver/drivers/remote_webdriver/#downloads

[VietND96]

For the API access contents in container, I think we will solve it once this feat #1626 able to implement