Add function to check if localization culture was already loaded. (#5603)

Robust.Shared/Localization/ILocalizationManager.cs

@@ -94,6 +94,12 @@ namespace Robust.Shared.Localization
         /// </summary>
         CultureInfo? DefaultCulture { get; set; }
 
+        /// <summary>
+        ///     Checks if the culture has been loaded.
+        /// </summary>
+        /// <param name="culture"></param>
+        bool HasCulture(CultureInfo culture);
+
         /// <summary>
         ///     Load data for a culture.
         /// </summary>

Robust.Shared/Localization/LocalizationManager.cs

@@ -337,6 +337,11 @@ namespace Robust.Shared.Localization
             }
         }
 
+        public bool HasCulture(CultureInfo culture)
+        {
+            return _contexts.ContainsKey(culture);
+        }
+
         public void LoadCulture(CultureInfo culture)
         {
             var bundle = LinguiniBuilder.Builder()