Allow popping out a Jitsi widget to respect Desktop web_base_url config (#12376)

* Allow popping out a Jitsi widget to respect Desktop `web_base_url` config

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

* Update tests

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

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Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/utils/WidgetUtils.ts

@@ -521,7 +521,7 @@ export default class WidgetUtils {
             // safe to send.
             // We'll end up using a local render URL when we see a Jitsi widget anyways, so this is
             // really just for backwards compatibility and to appease the spec.
-            baseUrl = "https://app.element.io/";
+            baseUrl = PlatformPeg.get()!.baseUrl;
         }
         const url = new URL("jitsi.html#" + queryString, baseUrl); // this strips hash fragment from baseUrl
         return url.href;