Change default pet-items to use type_spawn_egg instead of bones

[Nesseley]

Feature request

Short description As of now the class My Items are denied the use of pets because the items are obtainable in survival. 64 bones = 64 pets. Make the default item for pets be an item which you cannot get in survival.

Implementation details The new ID for a wolf would be wolf_spawn_egg and so on for . While it is possible now to change it yourself in the config.yml, I think it would be of great interest for removal of the pet block for My Items class and help with further reworks of the plugin if the default value for pets got changed.

Additional info This is a suggestion for when we drop support for old versions of Minecraft, as spawn eggs use NBT data in older versions.