feat: Improve error handling for unknown commands/subcommands

[Zarkness2]

During testing, I found the following errors.

When I type “/akarilevel help asd,” “{commandhelpasd}” appears. What comes to mind is to add a system that detects what help exists and, if one that does not exist is used, sends an error message indicating which one exists.

Then, if I enter the command “/akarilevel asd,” it sends me the following message. I think taboolib had a custom error handler.

“Invalid argument for command akarilevel asdalang:command.context.here.”

The same thing happens if I do the same test with subcommands, for example, “/akarilevel levelgroup asd.”

Also, when I type “/akarilevel member,” it doesn't work and gives me the above error.

edit

Currently, the plugin is completely unusable, as none or almost none of the commands can be used. Whatever command I use, I get the same error.

“Incorrect argument for command akarilevel asdalang:command.context.here”.

The right thing to do is, if you leave a command incomplete, to get a message saying something like “Incomplete command, use /akarilevel member has ”, not that error message.