Make update more visible when nothing was rendered yet

Description of the limitation and why it is relevant to address

As a user I want to have the update button for long duration calculations on views be more visible so that I know that the view will be rendered upon clicking on the button. At the moment the button in the right bottom corner is not always evident, whereby users get confused what to do, or whether they can render results.

I think this is relevant for the VIKTOR platform because it will improve user experience.

Submitter proposed design (optional)

A proposed design would be to have the button in the centre of the view, that is inviting to click on.

Current workarounds

Add text in the app to make it clear to the user that the update button should be clicked to render the view.