Expected behavior

\Bigcommerce\Api\Client::getTime() should fail on invalid store credentials, as documented

Actual behavior

\Bigcommerce\Api\Client::getTime() uses $api_url instead of $api_path so it effectively requests https://api.bigcommerce.com/time, which doesn't check for any store credentials.

On top of that, that endpoint returns timestamp in milliseconds, and getTime() parses is as seconds, so it returns bogus DateTime object

Steps to reproduce behavior

Run without any prior setup:

>>> \Bigcommerce\Api\Client::getTime()
=>  DateTime @1718280499756 {#5814
      date: 56420-02-21 18:49:16.0 +00:00,
    }