Koopa's Critters

Changelog:

Tweaks:
- Redid Spoonbill variant's code
- Redid Yangtze Softshell AI (They now have a fully aquatic AI similar to Fly River Turtles)
- Spoonbill & Oceanic Manta Rays can now be bred (with Fish)
- Kopje leaves now drop sticks & figs occasionally when mined with a hoe or by hand
- Koopas Critter's Birds now fall slowly
- Candy Cane Snails can now sometimes drop Goo when killed

Bugfixes:
- Fixed Penguin feather missing from feather tags
- Fixed Spoonbill Variants spawning naturally again
- Fixed some blocks to be able to be easily shears
- Fixed some blocks to be easily mined with hoe
- Fixed Attenborough's Echidna's Walk Animation
- Fixed Candy Cane Snail's Walk Animation
- Fixed all animations of South Island Takahe
- Fixed typo in Impala's name
- Fixed several animals being unable to breed
- Fixed Kopje Fig Leaves to behave more normally
- Cleaned up some code