This has been a pain point for a long time due to the misleading nature of the name "level". It's also confusing when trying to do things like getting the XP level of the player or such, and also does not translate well to other languages.
This transition was already executed on the UI some time ago (language strings) and now it's time for the same change to occur on the API.
This will burn a lot of plugins, but they'll acclimatize. Despite the scary size of this PR, there isn't actually so many changes to make. Most of this came from renaming `Position->getLevel()` to `Position->getWorld()`, or cosmetic changes like changing variable names or doc comments.
The reason this uses a trait is because `self` refers to the including class in a trait, which offers a small amount of automatic type safety.
If we had templates or generics, this would be a generic class instead.
This is similar in nature to 646fea5a4ecbbdf3f0cbfc590d874dedc1a7bfc0.
On a side note: Migrating this way is a pain in the ass due to lack of types. What the heck is int supposed to mean?!?!?!?! At least if we wanted to go _back_ to magic numbers, it would be easy to locate everything with an Enchantment typehint...
This introduces static getters for every currently-known effect type. At some point in the near future, the magic number constants (which are really network IDs, by the way) will disappear.
Migrating:
- If you used constants (like any sensible person would): for the most part it's just a case of adding a () anywhere you used an Effect constant.
- If you hardcoded magic numbers: ... well, have fun fixing your code, and I reserve the right to say "I told you so" :)
This achieves multiple goals:
1) creating an EffectInstance for application is much less verbose (see diff for examples, especially the Potion class)
2) plugin devs cannot use magic numbers to apply effects anymore and are forced to use type-safe objects. :)
This is a warning shot for plugin devs who use magic numbers. More changes like this are coming in the not-too-distant future.
