feat(service): add $translate.resolveClientLocale() (also at provider)

This is the expose of the internally used `getLocale()`.

```
$translate.resolveClientLocale()
$translateProvider.resolveClientLocale()
```

src/service/translate.js

@@ -547,6 +547,20 @@ function $translate($STORAGE_KEY, $windowProvider, $translateSanitizationProvide
     return $uses;
   };
 
+  /**
+   * @ngdoc function
+   * @name pascalprecht.translate.$translateProvider#resolveClientLocale
+   * @methodOf pascalprecht.translate.$translateProvider
+   *
+   * @description
+   * This returns the current browser/client's language key. The result is processed with the configured uniform tag resolver.
+   *
+   * @returns {string} the current client/browser language key
+   */
+  this.resolveClientLocale = function () {
+    return getLocale();
+  };
+
  /**
    * @ngdoc function
    * @name pascalprecht.translate.$translateProvider#storageKey
@@ -1881,6 +1895,20 @@ function $translate($STORAGE_KEY, $windowProvider, $translateSanitizationProvide
         return deferred.promise;
       };
 
+      /**
+       * @ngdoc function
+       * @name pascalprecht.translate.$translate#resolveClientLocale
+       * @methodOf pascalprecht.translate.$translate
+       *
+       * @description
+       * This returns the current browser/client's language key. The result is processed with the configured uniform tag resolver.
+       *
+       * @returns {string} the current client/browser language key
+       */
+      $translate.resolveClientLocale = function () {
+        return getLocale();
+      };
+
       /**
        * @ngdoc function
        * @name pascalprecht.translate.$translate#storageKey