…n't make sense

Previously, a lot of subcommands listed the --generate-dwarf option in cases
where no output file is produced, or where it doesn't make sense to add debug info.
This change refactors the options to separate the option to generate DWARF from
the generic input/output options.

The commands affected are: shrink, mutate, dump, objdump, strip,
demangle, `component wit`, `component targets`, and `metadata show`.
The --help messages for these commands no longer include --generate-dwarf.