A blocking modal (for now) saying that an invite is in progress * [ ] Web: https://github.com/element-hq/element-web/pull/30561 * [ ] Android: https://github.com/element-hq/element-x-android/pull/5342 * [ ] iOS: https://github.com/element-hq/element-x-ios/pull/4508
