支持更多音视频格式，添加点播测试页面

Example/SellyCloudSDK/Play/AVVodItemModel.m

@@ -0,0 +1,22 @@
+//
+//  AVVodItemModel.m
+//  SellyCloudSDK_Example
+//
+
+#import "AVVodItemModel.h"
+
+@implementation AVVodItemModel
+
++ (instancetype)modelWithUrl:(NSString *)url
+                       cover:(NSString *)cover
+                       title:(NSString *)title
+                        type:(NSString *)type {
+    AVVodItemModel *model = [[AVVodItemModel alloc] init];
+    model.url = url;
+    model.cover = cover;
+    model.title = title;
+    model.type = type;
+    return model;
+}
+
+@end