Update Chinese (Simplified) translations (#6005)

* i18n: (zh-CN) Remove spaces in time distances

* i18n: (zh-CN) Update translations for #5997

* i18n: (zh-CN) Add translation for #6004
also change translation of `staff` from `管理员` to `工作人员`

* i18n: (zh-CN) Add translations for #6003

* i18n: (zh-CN) Normalization