refactor: 增加异步支持

Author: ArgoZhang

src/components/BootstrapBlazor.HikVision/wwwroot/hikvision.js

@@ -86,6 +86,10 @@ const hackJSDestroyPlugin = function () {
         JSVideoPlugin = null;
         delete window.JSVideoPlugin;
         removePlugin();
+
+        return new Promise((resolve, reject) => {
+            resolve();
+        });
     }
 }