dovecot: refactor role

dovecot/defaults/main.yml

dovecot/files/sa-learn-ham.sh

dovecot/files/sa-learn-spam.sh

dovecot/tasks/main.yml

dovecot/templates/conf.d/10-auth.conf.j2

dovecot/templates/conf.d/10-mail.conf.j2

dovecot/templates/conf.d/10-ssl.conf.j2

dovecot/templates/conf.d/15-lda.conf.j2

dovecot/templates/conf.d/20-imap.conf.j2

dovecot/templates/conf.d/20-managesieve.conf.j2

dovecot/templates/conf.d/90-sieve.conf.j2

dovecot/templates/conf.d/99-dsync.conf.j2

dovecot/templates/deny-users.j2

dovecot/templates/dovecot.conf.j2

dovecot/templates/sieve/filter-spam.sieve.j2

dovecot/templates/sieve/report-ham.sieve.j2

dovecot/templates/sieve/report-spam.sieve.j2