[ECOM-470] Add `SoapOrderLineService`

This PR adds SoapOrderLineService, the last SOAP service for [ECOM-214] WOOOOOO. Should be pretty straight forward, we've done this a bunch of times now.

Please review: @ahoffmann @weizhong-wang @lloyd-carter

src/main/edu/wisc/services/cbs/api/SoapService.php

@@ -13,7 +13,7 @@ interface SoapService extends Service
      *
      * @param string $username  username
      * @param string $password  password
-     * @param \SoapClient|null $priceSoapClient  Overriding SOAP client (for testing purposes)
+     * @param \SoapClient|null $soapClient  Overriding SOAP client (for testing purposes)
      */
-    public function __construct($username, $password, \SoapClient $priceSoapClient = null);
+    public function __construct($username, $password, \SoapClient $soapClient = null);
 }