Split the installer into multiple subpackages & add Pulp installer

[ekohl]

Needs theforeman/foreman-installer#822.

To test:

dnf install https://yum.theforeman.org/releases/latest/el8/x86_64/foreman-release.rpm https://yum.puppet.com/puppet7-release-el-8.noarch.rpm
cat <<EOF > /etc/yum.repos.d/pulp-installer.repo
[pulp-installer]
name=Pulp Installer
baseurl=https://ekohl.nl/pulp-installer
gpgcheck=0
enabled=1
EOF
dnf install foreman-installer-scenario-pulp
. /etc/profile.d/puppet-agent.sh
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout /etc/pki/tls/private/localhost.key -out /etc/pki/tls/certs/localhost.crt
foreman-installer --pulpcore-servername $HOSTNAME --pulpcore-worker-count 1 --pulpcore-content-service-worker-count 1 --pulpcore-api-service-worker-count 1 --pulpcore-django-secret-key eep4quah0iatheehah9gai3Joo2quooThotahreethahgh0AhD --pulpcore-postgresql-db-password hagoa4see6ziefahthie7peigeega9E

Note that in my repo I haven't built the latest changes yet so you still need to hack the repo yourself.

[ehelms]

I was not expecting this part, that foreman-installer main package would have a requires on a scenario

[ekohl]

I still debated this in my head. I first wrote it here for compatibility or upgrades. Initially when I wrote this PR I really wanted to create a pulp installer and the split part was mostly to have a decent base to work on.

Perhaps we should not have foreman-installer as a real package anymore at all, just make all the scenarios Provide: foreman-installer = %{version}?

[ehelms]

Note you have this line in two places, katello-common and scenario-katello. I was leaning towards these two items should be included in either:

1. scenario-katello
2. foreman-installer-scenario-katello-certs (new sub-package)

[ekohl]

You may be right. I wasn't sure where we want to use this. Perhaps we shouldn't even name it an installer scenario and just make it katello-certs or something, since there's no separate scenario file it doesn't store any answers. It just provides a script to generate the certificates that could in theory also be used in some standalone server (like an offline CA).

[ekohl]

If we consider the downstream scenario then its own package makes sense.

[ekohl]

Note to self: this is missing %post sections to run the migrations. There we should actually make sure they exit with code 0 (by using || :). We may also need to redirect stderr to /dev/null since the logger complains about an unknown terminal if executed non-interactively via Ansible, or fix that in the installer/Kafo itself.

This came up in https://bugzilla.redhat.com/show_bug.cgi?id=2162704