fix: use setBaseUri for Verify2/ClientFactory

[Sysix]

Description

using setBaseUri for Verify2/ClientFactory instead of setBaseUrl

Motivation and Context

My Test-Setup with an PSR-18 Client will fail because it uses the Live-API for this request.

$client = new Vonage\Client(
    new Vonage\Client\Credentials\Basic(API_KEY, API_SECRET),
    [
        'base_api_url' => 'https://example.com'
    ],
    $myPSR18Client
);
// still on https://api.nexmo.com
$client->verify2()->startVerification(/* ... */);

How Has This Been Tested?

$myPSR18Client->method('sendRequest')->with(self::callback(static function(RequestInterface $request) {
  self::assertSame('https://example.com/v2/verify', $request->getUri()->__toString());
  return true;
}));
$client->verify2()->startVerification(/* ... */);

Example Output or Screenshots (if appropriate):

Expect that the Method will respect the base_api_url.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.