Provide a way to compare tags more easily

Proposal

Add a button or menu options to allow the user to compare.

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When looking at tags, there is a workflow to compare it against another tag/branch to see the difference in commits.

Seeing the commits between two tags is good if you can see it all in one list. However there are some scenarios where it is would be easier to set up the compare view to view the range of commits between two tags.

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from #18795 (comment 1196915152)

So the /commits list with tags would provide me with similar information as the top part of the compare page (e.g. https://gitlab.com/gitlab-org/gitlab-shell/-/compare/v14.11.0...v14.12.0?from_project_id=14022&straight=false). However, rather than having to enter two tags to compare, I would simply scroll through the list.

@igor.drozdov however explained that the following statement is not 100% correct

Every commit in the commits list before (and including) the commit that was tagged as release version version x and after the commit that was tagged as version x-1 must have been released in release x.

The statement is not 100% correct. In the /commit list view, commits are ordered by time. So, it could be that someone committed something in a feature branch before a tag was set in the main branch but only merged the feature branch into main after the tag was set. Then this earlier commit will be shown below the tag but is not included in the tag as the merge commit of the branch only happened after the commit. In the compare view it would not be included. (e.g. comparing x and x-1 tags: https://gitlab.com/gitlab-org/gitlab-shell/-/compare/v14.11.0...v14.12.0?from_project_id=14022&straight=false)

When we scroll this page: https://gitlab.com/gitlab-org/gitlab-shell/-/commits/main, from time to time we will see the release version. This is when the release was cut/tag was created. But a release does not necessarily contain every commit below it.