Port CommandSettings (of Vhoyon/Discord-Bot) to abstract version in here

[V-ed]

As we advertise that our framework handles setting, we should also provide the ability to easily create a settings command with an abstract interface to deal with settings.

Since dealing with settings may mean more than simply setting a value, we would need to handle callbacks and deal with langs too.

This is the command currently implemented in our own bot, which we would port in here :
https://github.com/Vhoyon/Discord-Bot/blob/69256eb4df14005eb09f06fea60ac7a3e7f0bd2c/src/main/java/io/github/vhoyon/bot/commands/CommandSetting.java