[NOT TESTED] Gigas Spirit Ball implementation

* Added the new enemy spirit ball. Go randomly until Gigas ask to regroup which trigger a target move ignoring all and going to the target in ~2 seconds
* Changed how Gigas is reappearing (split the function between teleport and appear, teleport should be renamed)
* Fixed a non-sense in the code when getting random data from a table, due to Agahnim example L64.