Separate inventory holder info from container & player inventories (#6533)

This PR breaks the cyclic dependency between `Inventory` and its holder, which unblocks a lot of new developments.

### Related issues & PRs
- Fixes #5033
- Removes a blocker for #6147 (which in turn means that async tasks will eventually be able to work with tiles)
- Removes a blocker for #2684

## Changes
### API changes
- `Player->getCurrentWindow()` now returns `?InventoryWindow` instead of `?Inventory`
- `Player->setCurrentWindow()` now accepts `?InventoryWindow` instead of `?Inventory`
- `InventoryWindow` introduced, which is created for each player viewing the inventory, provides decorative information like holder info for `InventoryTransactionEvent`, and is destroyed when the window is closed, eliminating cyclic references
- Added:
  - `player\InventoryWindow`
  - `player\PlayerInventoryWindow` - wraps all permanent inventories of Player with type info for transactions
  - `inventory\Hotbar` - replaces all hotbar usages in `PlayerInventory`
  - `Human->getHotbar()`
  - `Human->getMainHandItem()`, `Human->setMainHandItem()`, `Human->getOffHandItem()`, `Human->setOffHandItem()`
  - `block\utils\AnimatedContainerLike` & `block\utils\AnimatedContainerLikeTrait` (for chests, shulkerboxes, etc)
  - `block\utils\Container` & `block\utils\ContainerTrait` for blocks containing items (chests, etc)
  - `block\utils\MenuAccessor` implemented by all blocks that can open inventory menus
  - `block\utils\MenuAccessorTrait` used by blocks with menus but without inventories (anvils, crafting tables etc)
- Removed:
  - `inventory\DelegateInventory` (only used for ender chests)
  - `inventory\PlayerInventory`,
  - `inventory\PlayerOffHandInventory`,
  - `inventory\PlayerCraftingInventory`,
  - `inventory\PlayerCursorInventory` - these have all been internally replaced by `SimpleInventory` & they will appear as `PlayerInventoryWindow` in transactions (check `getType()` against the `PlayerInventoryWindow::TYPE_*` constants to identify them)
  - `block\inventory\AnimatedBlockInventoryTrait`, (blocks now handle this logic directly using `AnimatedContainer` and `AnimatedContainerTrait`)
  - `block\inventory\BlockInventoryTrait`,
  - `block\inventory\BlockInventory`
- Most `BlockInventory` classes have been transitioned to `InventoryWindow` wrappers
- Tiles now all use `SimpleInventory` internally (no cyclic references) except for `Chest` (which uses `CombinedInventory`, without holder info)
- `InventoryOpenEvent` and `InventoryCloseEvent` now provide `InventoryWindow` instead of `Inventory` (to provide type information)
- `InventoryTransaction` and `SlotChangeAction` now provide `InventoryWindow` instead of `Inventory`
- Renamed `TransactionBuilderInventory` to `SlotChangeActionBuilder`
- `TransactionBuilderInventory->getBuilder()` now accepts `InventoryWindow` instead of `Inventory`
- `DoubleChestInventory` superseded by `CombinedInventory` - this new class allows combining any number of inventories behind a single object; mainly used for double chests but plugins could use it to do lots of fun things

### Impacts to plugins
Plugins can now do the following:
```php
$block = $world->getBlockAt($x, $y, $z);
if($block instanceof MenuAccessor){
    $block->openToUnchecked($player);
}
```
As compared to the old way:
```php
$tile = $world->getTileAt($x, $y, $z);
if($tile instanceof Container){
    $player->setCurrentWindow($tile->getInventory());
}
```

#### Advantages
- No tile access needed
- Works for menu blocks without inventories as well as container blocks
- Less code

### Behavioural changes
Inventories no longer keep permanent cyclic references to their holders.

## Backwards compatibility
This makes significant BC breaks. However, all changes are able to be adapted to and the same amount of information is present on all APIs and events.

## Follow-up
- Implement #6147 
- Support inventory inheritance when copying blocks from one position to another

src/block/utils/MenuAccessorTrait.php

@@ -0,0 +1,58 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+ */
+
+declare(strict_types=1);
+
+namespace pocketmine\block\utils;
+
+use pocketmine\block\Block;
+use pocketmine\item\Item;
+use pocketmine\math\Facing;
+use pocketmine\math\Vector3;
+use pocketmine\player\InventoryWindow;
+use pocketmine\player\Player;
+use pocketmine\world\Position;
+
+trait MenuAccessorTrait{
+
+	/**
+	 * @see Block::onInteract()
+	 */
+	public function onInteract(Item $item, Facing $face, Vector3 $clickVector, ?Player $player = null, array &$returnedItems = []) : bool{
+		if($player instanceof Player && !$this->isOpeningObstructed()){
+			$this->openToUnchecked($player);
+		}
+
+		return true;
+	}
+
+	abstract protected function newMenu(Player $player, Position $position) : InventoryWindow;
+
+	public function isOpeningObstructed() : bool{
+		return false;
+	}
+
+	abstract protected function getPosition() : Position;
+
+	public function openToUnchecked(Player $player) : bool{
+		return $player->setCurrentWindow($this->newMenu($player, $this->getPosition()));
+	}
+}