list_operate: Add in and out parameters

.gitlab-ci.yml

README.md

docs/api/usp.md

docs/api/usp.raw.md

gitlab-ci/functional-test.sh

gitlab-ci/install-dependencies.sh

schemas/ubus/usp.json

schemas/ubus/usp.raw.json

src/add_delete.c

src/common.h

src/get_helper.c

src/operate.c

src/pretty_print.c

src/set.c

src/usp.c

test/cmocka/unit_test_uspd.c

test/files/etc/config/cwmp

test/files/etc/config/uspd

test/python/validate_3272.py

test/python/validate_fault_code.py