Access raw commands from executor

[DerEchtePilz]

Description

Currently, when adding an executor to a command, you cannot retrieve the raw command string.
For most argument combinations it is pretty easy to convert an Object into a String (for example: turning a Player into a String using Player#getName() or turning any primitve types into strings)

However, this gets pretty difficult when using the EntitySelectorArgument which lets you input selectors (@a, @e, etc.) which can produce the exact same result.

Thus it would be useful if the CommandAPI implemented a way to retrieve the raw command string in the executor.

Expected code

In order to implement this, the CommandAPI could add a new method to the CommandArguments class like this:

public String getFullInput() {
    // Return whatever the user entered as a command
}

Extra details

For anyone wanting to implement this, the CommandArguments class is filled with information in the CommandAPIHandler. In there, there is a method called argsToCommandArgs which populates that with content.

[JorelAli]

Implemented in 9.0.0.