Feat: set default expiration minutes when no value passes in args for temp url

[chinmaypurav]

Most of the time I work with temporary URLs when working with private media. It is very cumbersome to set the expiration time for every $model->getFirstTemporaryUrl(now()->addMinutes(5))

To overcome this, I am submitting this PR, where, if no arg is passed, a default time is set, can be configured from config.

This want I can do

// Before
$model->getFirstTemporaryUrl(now()->addMinutes(5));

// After
$model->getFirstTemporaryUrl();

[freekmurze]

Thanks!