Set output-file through metadata

[cderv]

This is related to this discussion

• Project not working correctly after overriding output name quarto-cli#12923 (reply in thread)

--output is not behaving the same as output-file config. It is not handled by the same code path in Quarto, and some feature gets messed up like Other Formats

Probably using output-file metadata is best.

Related to

• quarto_render not supporting both multiple output formats and a specified output file name #43