[Web][Restic][Dovecot][Dockerapi] Add restic backups with restore in the UI

- Scheduled, encrypted backups to S3, SFTP, REST or a local folder (new restic-mailcow container)
- Restore of mailboxes and whole domains in the UI, also deleted ones, for admins and domain admins
- Scope set by RESTIC_BACKUP_MODE in mailcow.conf (all, data, config)
- Optional backup before updates (update.sh), helper-scripts/restic.sh for a full restore

data/Dockerfiles/restic/Dockerfile

@@ -0,0 +1,28 @@
+FROM alpine:3.24
+
+LABEL maintainer="The Infrastructure Company GmbH <info@servercow.de>"
+
+ENV LANG=C.UTF-8
+ENV LC_ALL=C.UTF-8
+# MariaDB Connector/C >= 3.4 refuses DB servers without TLS, the runner connects through the socket
+ENV MARIADB_TLS_DISABLE_PEER_VERIFICATION=1
+
+RUN apk add --no-cache --update \
+  ca-certificates \
+  git \
+  mariadb-client \
+  openssh-client \
+  py3-mysqlclient \
+  py3-pynacl \
+  python3 \
+  restic \
+  tini \
+  tzdata \
+  # dump, export, manifest and the mailcow directory are below /mailcow (paths of the snapshot), only root may read them
+  && mkdir -m 700 /mailcow
+
+COPY restic_runner.py /usr/local/bin/restic_runner.py
+COPY sogo_restore.py /usr/local/bin/sogo_restore.py
+
+ENTRYPOINT ["/sbin/tini", "--"]
+CMD ["/usr/bin/python3", "-u", "/usr/local/bin/restic_runner.py"]