Stamina Attributes

# Stamina Attributes This API adds a stamina system controlled by entity attributes. ## Default implementation LivingEntities can have up to **_staminaattributes:max_stamina_** amounts of stamina. Stamina is regenerated by **_staminaattributes:stamina_regeneration_** every **_staminaattributes:stamina_tick_threshold_** ticks. When stamina is reduced, regeneration is stopped for **_staminaattributes:stamina_regeneration_delay_threshold_** ticks. When stamina is