Glitchy interface jumping/flickering bugs

[connyduck]

I hate when software shows stuff just of a split second and then something else. Unfortunately we have some instances of that as well:

• When opening the app while offline, the failing network causes the error screen to pop up, but is quickly hidden by posts loaded from the cache. The error should only be shown when there are no cached posts. Happens on home timeline and since Refactor notifications to Kotlin & paging #4026 also in the notification tab.
• When changing the image visibility in the home timeline and then opening the post in the detail view, the image is shown with the visibility it had in the timeline, but then quickly changed back to its original state.
• When refreshing posts in the detail view the whole screen flickers, probably because the full screen loading spinner is shown instead of just the swipe refresh spinner.
• When changing image visibility/expanding content warnings at the top of the timeline and then reopening the app they are sometimes quickly switched back to their original state. This happens because sometimes the network refresh is faster than loading posts from cache and the check that should prevent the bug has no old post to compare. Possible solution: Wait for the cache to be available before making the network refresh.
• when interacting with posts (e.g. liking) that have media attachment, sometimes the preview flickers