common/parser: add `--skip-chat-parsing` to force a pure content parser. (#20289)
* Add `--force-pure-content` to force a pure content parser.
* Update common/arg.cpp
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
* Change parameter name [no ci]
---------
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>