Consider caching the profile view states during the view switch

After #2478, we are recomputing the profile view data when we are switching views. It's good to recompute because data structures will be different. But we should have a way to cache those views in case we want to switch back to that view again.

Also we would want to figure out how to do that transition UI wise. Right now we are displaying the loading screen again, which is pretty disruptive (I want it to be). But Greg's feedback was about it being too much. Maybe we can have a dimming or blurring effect during this switch instead of completely hiding the profile view UI.

┆Issue is synchronized with this [Jira Task](https://mozilla-hub.atlassian.net/browse/FP-251)