Set fallback_url from application instace

[jazz7381]

I want to set fallback_url

Expected Behavior

I want to set voice fallback url like set event and answer url from application instance.

Example:

$application->getVoiceConfig()->setWebhook(\Vonage\Application\VoiceConfig::ANSWER, new \Vonage\Application\Webhook($data['voice_fallback_url_address'], strtoupper($data['voice_fallback_url_method'])));

Current Behavior

Possible Solution

Add method to set voice fallback url

Steps to Reproduce (for bugs)

Context

Your Environment

• Version used: "vonage/client-core": "^2.0"
• Environment name and version (e.g. PHP 7.2 on nginx 1.19.1): PHP 7.4 on Apache
• Operating System and version: Windows 10 with WSL