World specific options on "Select World" screen remain enabled when no world is selected

The bug

World specific buttons, such as "Play Selected World", on the "Select World" singleplayer world selection screen remain enabled even when no world is visibly selected. This is pretty confusing because it is not clear which world the "selected" one is.

There are two ways to reproduce this, see below.

Reproduction steps (search)

1. Select a world using the TAB (↹) key
2. Keep pressing TAB until the search bar at the top has focus
   The world selected previously should still have a gray outline
3. Type something in the search bar which does not match the name of the world
   The world is no longer shown, but the buttons, such as "Play Selected World" are still enabled

Expected: As soon as the user starts searching the world selection is updated. Either...

• the selection is cleared
• the selection is cleared when the previously selected world is omitted because it does not match the search text
• Preferred (?): once the user starts typing in the search bar, the first matching world (if any) (which is not open in another instance of Minecraft!) is selected

Reproduction steps (clicking with mouse)

1. Select a world by clicking on its name and description (but not on the play button)
   The world specific buttons, such as "Play Selected World" are enabled
2. Click at the search bar at the top of the screen
   The previously selected world has no outline anymore but the world specific buttons as still enabled

Expected (all of these):

1. Clicking on an entry on the list adds a white instead of gray outline (to be consistent with pressing TAB)
2. Clicking at the search field does not remove the selected world outline, but only turns it gray