Add basic auth feature and SSL feature.

[harajune]

Issues

• AudioFileSourceHTTPStream lacks a basic auth feature.
• Also, SSL.

What I created

• add setAuthorization method to AudioFileSourceHTTPStream. This method will set the basic auth setting to HTTPClient.
• add setClient method to AudioFileSourceHTTPStream. This method enables users to use WiFiClientSecure to set a root CA certificate.

Sample

wifi_client = new WiFiClientSecure();
wifi_client->setCACert(ROOT_CA);

file = new AudioFileSourceHTTPStream();
file->setClient(wifi_client); // here
file->setAuthorization(BASIC_USER, BASIC_PASS); // here
file->open(url);
buff = new AudioFileSourceBuffer(file, 2048);
out = new AudioOutputI2S(0, 1);
out->SetOutputModeMono(true);
out->SetGain(1.0);
mp3 = new AudioGeneratorMP3();
mp3->RegisterStatusCB(StatusCallback, (void*)"mp3");
mp3->begin(buff, out);

[earlephilhower]

Minor thing related to URL size change, but generally looks good. Thanks!