[FR] Ability to remove custom key

Hi! It would be cool if it was possible to delete a custom key when it is no longer needed.

Example: when entering the game screen, I create a custom key "level_config", in which I specify some data (level id and etc.). After exiting the game screen, I no longer need to see this key in the list in the next possible error (of course, if it happened not on the game screen).

Now I can clear the key value, but it will still remain in the list. If there are many such keys depending on some condition, then the list will turn into a mess!