Clicking the call button when a widget is maximised should open the call in the right panel

### Your use case

#### What would you like to do?
I am organising a game night using Element and widgets. I make use of the new maximised widget feature for the games (widgets), start a voice call (Jitsi) in the right panel and set my room layout for everyone.

When a participants joins the room they will see the maximised widget in the in the middle and the chat in the right panel. Now I want them to be able to easily join the voice call without disrupting the maximised widget.

#### Why would you like to do it?
I am doing this for non-tech people who are partly completely new to Element and Matrix and are easily confused, so I can not just explain them how you navigate to the widgets section and change your room layout etc.

#### How would you like to achieve it?
The call button should open an ongoing call in the right panel if a widget is maximised.

### Have you considered any alternatives?

Let me include the right panel when I set my room layout for everyone, making it possible for them to already have the call opened in the right panel when opening the room for the first time. (https://github.com/vector-im/element-web/issues/21054) The described problem would still occur as soon as they want to navigate to the chat and try to go back to the call using the dedicated button.

### Additional context

_No response_