Roles were reversed in original code.

This makes the extension of the registered item available at evaluation time,
which is e.g. needed to access the extension context.

plugins: doveadm-sieve: doveadm-sieve-sync - Refactor error handling in sieve_attribute_set_active()

Makes code easier on the eyes.

For consistency with managesieve.

Also make code cleaner and consistent.

For consistency with managesieve_capabilities_dump().

lib-sieve: plugins: enotify: ext-enotify-common - Rework error handling to match extension API changes