global: Remove sieve_ event field prefixes

src/lib-sieve/cmd-redirect.c

src/lib-sieve/plugins/enotify/mailto/ntfy-mailto.c

src/lib-sieve/plugins/notify/cmd-notify.c

src/lib-sieve/plugins/vnd.dovecot/report/cmd-report.c

src/lib-sieve/sieve-actions.c

src/lib-sieve/sieve-interpreter.c

src/lib-sieve/sieve-result.c

src/lib-sieve/sieve-script.c

src/lib-sieve/sieve-storage.c

src/managesieve/cmd-putscript.c

src/managesieve/cmd-setactive.c

src/plugins/sieve-extprograms/cmd-pipe.c