Changes

Support `body` equipment slot (#2736)

* EntityBodyArmor property, `body` argument in `equip` command

* 1.20+ clarified

* slight condition change

* slight correction

* slight fix

* moved body_armor exclusively under `equip` command and as part of `EntityTag.equipment` and `EntityTag.equipment_map`

* added `body_armor` tag to go along with previous `horse_armor`

* deprecated EntityTag.equipment, other minor changes

* removed EntityTag.body_armor

* deprecation file

* minor changes

* deprecation message fix

* -_-

* slight clarification
 (commit: 4e6c6f7)