Новая команда `picodata plugin` и подкоманда `picodata plugin configure`

Picodata follow-up

• Follow-up for new cli command to update plugin service config (picodata!1389)
• See also Load plugin service configuration from it's con... (picodata#705)
• Doc pages to change: https://docs.picodata.io/picodata/stable/reference/cli