add new role for dovecot

dovecot/handlers/main.yml

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-master.conf.j2

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

dovecot/templates/conf.d/auth-passwdfile.conf.ext.j2

dovecot/templates/dovecot.conf.j2