automatic snapshot import for rpm packages.

What

This MR is a follow-up for !15552 (merged) in order to have a similar user experience also for rpm packages.

NB: the first commit is part of !15552 (merged)

Why

How

I adapted the scripts used to download the snapshot and added to the rpm packages. I moved the test with systemd to scripts/packaging/tests/rpm/rpm-install.sh as I don't want to pollute the documentation ( some part of the doc are sourced from docs/introduction/install-bin-rpm.sh ) with implementation details.

Manually testing the MR

# we use fedora because alien and rpmrebuild exist as packages
FROM fedora:39

SHELL ["/bin/bash", "-o", "pipefail", "-c"]

RUN dnf -y update
RUN dnf -y install 'dnf-command(config-manager)'
RUN dnf -y config-manager --add-repo  https://storage.googleapis.com/tezos-linux-repo/next/abate%40rpm-experience/rockylinux/dists/9.3/
RUN dnf -y update
#RUN dnf clean all
RUN rpm --import https://storage.googleapis.com/tezos-linux-repo/next/abate%40rpm-experience/rockylinux/octez.asc
#RUN dnf repolist -v
RUN dnf -y install octez-client
RUN rpm -v --info -q octez-client
RUN rpm -v --verify octez-client

you can use this dockerfile to build and install packages

or build packages locally using scripts/packaging/build-rpm-local.sh

You can see a successfull pipeline here : https://gitlab.com/tezos/tezos/-/jobs/9049530569

you can repeat this test locally with

DISTRIBUTION=rockylinux RELEASE=9.3 scripts/packaging/tests/systemd-docker-test.sh scripts/packaging/tests/rpm/rpm-install.sh images/packages/rpm-systemd-tests.Dockerfile 

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR