Add a PaperMC platform optimization

This will allow the api to not use Arrays.asList().contains(invoker.getType()); into validators

Currently the args are stored as String[] in the CommandContext.
This can be fairly annoying when working with type of args that aren't strings.

A custom argument api could make it easier.

Do some benchmarking on some components of Hardened to make sure there is no critical flaws in terms of performance

Add a Velocity platform implementation

Improve the readability of the javadocs and use annotations such as @NotNull to improve the usage experience.

Paper & Bukkit invokers are the same so we should share them.

Move stuff that is common to Velocity, Paper and Brigadier to the upcoming Brigadier impl

Right now, the argument system can feel overwhelming to use. A complete recode of the argument system could benefit the project.

Add a Bungeecord platform implementation

• Standardize all of the Invoker types into one that contains all of the required info
• Make a cleaner way to create them