[Bug]: A set Game Install folder has been moved/removed causes an error

[ItsEasyActually]

Users who move or uninstall their game folders will have an error when loading the Manager. A check is needed to prompt the user to select the correct location for the game install if an error is thrown on checking the game install location.

Behavior should allow the user to select the correct folder through the same behavior as the Add Game button. If the user chooses to cancel re-adding the game, we should have it remove the game from the manager's list of added games.

Reference error