Pulp

As a pulp_installer user, I can install Pulp from RPMs

Heavily adapted from "allow installing pulp from packages"

https://github.com/pulp/pulp_installer/pull/188

Includes:

1. Dropping the fixed repo from the old PR.
2. Add var pulp_pkg_repo (currently only yum/dnf)
3. Finish cleaning up pulp_webserver_static_dir
4. Many new variables, but still using the overall pulp_install_plugins.
5. Testing upgrades with new images on quay (can't truly test until RPM updates are issued)
6. Cron/branch CI: Adding py38 testing
7. PR CI: Move upgrade testing from py37 to py38, and testing from RPMs on py37.
8. Deduplicating the tasks for checking plugins for nginx/apache snippets.
9. Using pulp_django_admin_paths list var because RPMs often use different names for django-admin.
10. Note: Rest of tasks should be package manager independent.
11. pulp_upgraded_manually variable in case users ran yum update
12. package only variables in seperate section of the pulp README.md.

fixes: #6793

Includes these subtasks implemented: re: #6794 re: #6795 re: #6796 (It was easiest to implement them all in one PR.)

As a pulp_installer user, I can install Pulp from RPMs

Heavily adapted from "allow installing pulp from packages"

https://github.com/pulp/pulp_installer/pull/188

Includes:

1. Dropping the fixed repo from the old PR.
2. Add var pulp_pkg_repo (currently only yum/dnf)
3. Finish cleaning up pulp_webserver_static_dir
4. Many new variables, but still using the overall pulp_install_plugins.
5. Testing upgrades with new images on quay (can't truly test until RPM updates are issued)
6. Cron/branch CI: Adding py38 testing
7. PR CI: Move upgrade testing from py37 to py38, and testing from RPMs on py37.
8. Deduplicating the tasks for checking plugins for nginx/apache snippets.
9. Using pulp_django_admin_paths list var because RPMs often use different names for django-admin.
10. Note: Rest of tasks should be package manager independent.
11. pulp_upgraded_manually variable in case users ran yum update
12. package only variables in seperate section of the pulp README.md.

fixes: #6793

Includes these subtasks implemented: re: #6794 re: #6795 re: #6796 (It was easiest to implement them all in one PR.)