Refactor and clean up of ci jobs

Summary

This MR is a clean-up and slight refactoring of the ci jobs and stages. The most notable changes are:

• Job names are now kebab-case, following the common naming convention
• Job names are more consistent with each other
• The order of the items under each job is now consistent
• Indentation fixes
• Expanded certain single-line if statements into multiple statements to make them easier to read
• Extracted build-tagged.gitlab-ci.yml from release.gitlab-ci.yml. This way it is grouped with the other build stages in the directory file list
• Removed anything related to xrootd or eos version 4 from the ci and the build scripts
• Separated out job to publish to testing repo from the job that publishes to our internal repo
• Renamed dockerimage.gitlab-ci.yml to build-image.gitlab-ci.yml to make it consistent with the other build stages and group them nicely.
• Renamed kube-tests.gitlab-ci.yml to tests-kubernetes.gitlab-ci.yml to group it with the other test stage.
• Moved the part for creating the local repo to the before scripts in tests.gitlab-ci.yml
• Renamed the build:dockerimage to build:image
• Renamed build:tagged_rpm to build:tagged
• Split the release stage into release:internal and release:external
• Extracted variables that defines which images to use (#35 (closed))
• Removed references to cc7 and changed remaining jobs to alma9

Additional Required Actions

• Requires manual tests in pre-production: NO

• Requires a documentation update: YES #807 (closed)

References

Closes #808 (closed) Closes #799 (closed) Closes #798 (closed) Closes #800 (closed) Closes #35 (closed)