Several verbs in the STANDALONE bucket accept --json=, but that bucket only
offers --help --version --system --user --global --no-pager, so completion
never suggested the option for them.
Split those verbs out into a new STANDALONE_JSON bucket that additionally
offers --json=off/pretty/short. The verbs are moved rather than copied, as
${VERBS[*]} is used to complete the verb list itself.