Adjusted to change in Dovecot Storage API.

src/lib-sieve-tool/mail-raw.c

src/lib-sieve/plugins/mailbox/tag-mailbox-create.c

src/lib-sieve/plugins/mailbox/tst-mailboxexists.c

src/lib-sieve/sieve-actions.c

src/testsuite/testsuite-mailstore.c