Exposes a new suspicious effect entry type that properly represents
storable effects in the context of suspicious effects as they only
define the potion effect type and duration.
This differentiates them from the existing PotionEffect API found in
bukkit and hence clarifies that storable values in the parts of the API
in which it replaces PotionEffect.
Co-authored-by: Yannick Lamprecht <yannicklamprecht@live.de>
