Re-enable screenshots component

If one opens the context menu with a right-click on any website you have the option to take a screenshot in Firefox. That's not available in Tor Browser for desktop. I know we restrict the screenshot functionality on Android (#41195 (closed)) but there is no reason to do the same for desktop, I think. This results in me needing to resort to plain Firefox when trying to take a screenshot of some Grafana boards :( (see: tpo/tpa/team#40866 (closed) for the TPA issue with some discussion).