Implement Brewing

[VixikHD]

Introduction

This pull request implements basic Brewing stand functionality.

Relevant issues

• There is no issue related to this pull request

Changes

API changes

• New pocketmine\event\inventory\BrewingFuelUseEvent and pocketmine\event\inventory\BrewItemEvent events
• Added methods BrewingStandInventory->getIngredient(): Item, BrewingStandInventory->setIngredient(Item): void, BrewingStandInventory->getFuel(): Item and BrewingStandInventory->setFuel(Item): void

Behavioural changes

• Brewing stand is now implemented

Backwards compatibility

• None

Tests

https://streamable.com/4ma0lh

[dktapps]

I haven't reviewed this in-depth yet, but it's looking interesting.

[dktapps]

This looks good so far, but there are a few things that should be addressed.
Also, the formatting is inconsistent in some places - if you use PhpStorm, please reformat your code using the provided Project code style.

[dktapps]

Please reformat the code using the provided Project code style.

[dktapps]

I think this is now more or less ready to merge.

I will note that the one thing I'm unhappy about is the exposure of legacy item IDs to the API in PotionContainerChangeRecipe. However, this is a hard problem to solve given currently available API, so I don't consider it a showstopper.