common: support negated args (#17919)
* args: support negated args
* update docs
* fix typo
* add more neg options
* Apply suggestions from code review
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
* rm duplicated arg
* fix LLAMA_ARG_NO_HOST
* add test
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Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
