Changes

`Glow` command rewrite (#2466)

* WIP rewrite, add helper for `glow` and `invisible`

* `perPlayerMap` -> `packetOverrides`

* Prefix isn't required for enum args (`state:`)

* Update meta

* Remove `state:` tab-complete

* `applyByteFlag` -> `applyEntityDataFlag`, imports

* Slight cleanup/opti

* Optimize `setForPlayers` modification checking

* Minor code cleanup

* Use `Predicate` instead of `Function<X, Boolean>`

* Fix `isGlowing` (only need the bukkit method)

* Move `EntityMetadataCommandHelper` to `utilities`

* Move `GlowCommand` to `entity` package + group

* Lowercase `state` argument default value

* Fix `invisible` command syntax meta
(commit: 8976f3f)