[Enhancement] Kotlin Extensions for AutoCompleter

[TehNeon]

There are currently no extensions or additional functions for the AutoCompleter system. This currently results in having to write some pretty ugly looking code.

What the code looks like in Kotlin currently:

commandHandler.autoCompleter.registerParameterSuggestions(String::class.java) { args, sender, command ->
    emptyList<String>()
}

What it could look like in Kotlin (This example follows the current naming scheme of the extensions):

commandHandler.autoCompleter.parameterSuggestions<String> { args, sender, command ->
    emptyList<String>()
}

[Revxrsal]

Yes, auto-completer extensions should be implemented. Will get to this soon :)

[Revxrsal]

Added in https://github.com/Revxrsal/Lamp/commit/6eee6ccd6eca864b6d318d5f014f20cd465104ac.