Changes GetBlockBlobReference to be public

Not a common scenario but it is nice to have this method public in case you want direct access to the blob storage configured for the media provider instead of having to setup up all of the connections manually based on the file system provider settings.

Author: Shazwazza

src/UmbracoFileSystemProviders.Azure/AzureFileSystem.cs

@@ -780,7 +780,7 @@ public static CloudBlobContainer CreateContainer(CloudBlobClient cloudBlobClient
         /// <returns>
         /// The <see cref="CloudBlockBlob"/> reference.
         /// </returns>
-        private CloudBlockBlob GetBlockBlobReference(string path)
+        public CloudBlockBlob GetBlockBlobReference(string path)
         {
             Current.Logger.Debug<AzureBlobFileSystem>($"GetBlockBlobReference(path) method executed with path:{path}");