Add CommandArguments#getOrThrow

### Description

Even tho there is `CommandArguments#getOptional`, I think `CommandArguments#getOrThrow`-like (`#getUncheckedOrThrow` etc.) would be easier to use and much shorter than whatever this is:
`args.<String>getOptionalUnchecked("name").orElseThrow()`

### Expected code

basically `CommandArguments#getOrThrow`

### Extra details

_No response_