Use %version_override/%release_override to specify version/release by users
    
    When backporting the latest changes to CentOS Hyperscale reviewers
    were confused by using %version and %release to define "Version" and
    "Release" which are supposed to specify the values for %version and
    %release. Let's use different macros to make it more clear that these
    are supposed to be set by users building the rpm and add a comment
    to explain why we do this.