Fixes for textured heads & creative inventories

[Ampflower]

• Adds a GolfIV tag on items while in creative.
  • To ensure that all creative players get this tag...
    • The inventory is resent every time they switch to creative.
    • The inventory is always minimised and treated as overflown when in creative.
      • This does mean that items in creative maybe lacking NBT on the client, and thus, may not render some items like shulker boxes correctly.
• Adds fixes for player heads not rendering as expected when worn or on the ground.
• Added a fix for crossbows not showing if they're loaded. To other clients, they'll only see either a firework or an arrow.
• Items in creative will no longer be wiped of NBT if the NBT already exists in the inventory.
  • This however does rely on the patchItemKickPatch in its current state. It will fall through to the sanitiser if disabled.
• Some NBT string references in the minimizer methods has been swapped out to use the strings from items.
• The creative items check now has unnecessary-javadocitus

Fixes #41 - Creative inventories no longer get inadvertently sanitised for preexisting items by both patchItemKickExploit and removeCreativeNbtTags
Fixes #48 - Item names and heads show as expected now.
Needs verification for #45 for as this may fix the issue.

[Ampflower]

Moving a head around in the inventory, for some reason, the Display tag is not getting sent. Although, interestingly, this only happens in the creative inventory. Other inventories don't show this effect.
This might be due to a disparity of usage within packets for open inventories, although the issue only showing itself on the main inventory makes me wonder otherwise.

[Ampflower]

Force-push was to make the history more sane, and to revert the change to ItemStackChecker#fakeStack.

The one significant change from before the force-push is that usage of fakeStack in patchItemKickExploit was replaced with inventoryStack.

[Ampflower]

Fixed a typo and now have made crossbows send correct data to all clients.