deleteFavorite
Deletes an existing favorite.
This method removes the specified favorite from the list of favorites. If the deletion is successful, the listener, if provided, will be notified via its onSuccess callback. If there is an error during the deletion process, the listener's onError callback will be invoked.
Parameters
favorite
The IRainbowFavorite object representing the favorite to be deleted.
listener
An optional RainbowListener that will be notified of the result of the delete operation. The listener receives a Unit result on success or an error indication on failure.